It is a kind of crutch, but it depends on what you expect from online chess.
If you use it as a substitute to OTB play (to play long games), then I would recommend not using the analysis board.
If you use it for research purposes, or for fun, then why not use the analysis board.
If you want to reach a rating USCF or FIDE of 2200+ the only diagram or chessboard that you will ever need be it playing a game or reading a chess book is the diagram or chessboard in your head.
Using machines for anything other than studying openings or preparing for a tournament are damaging to your analytical strength.
Thanks to all for your advice. Since I'm trying to improve my USCF standing, I think I will forgo using the analysis tool.
Trust yourself. If you are wrong, then you know where the problem lies - it's only a weakness you have to work on to get rid of.
I think this is other way of cheat, but don´t worry, lot of people do the same here.
I resigned a online tournament a couple of month ago (I dropped 100 ELO points but it doesn´t matter) because all the low rated players in my group were cheating me with programs.
If you want to analyze your games do it when it finished just like I use to do.
@The Bruce - don't agree that it is cheating. The tool does not provide computerized analysis or suggested moves during the game. All it does is provide you with a chess set to move through various scenarios. I'm not aware of any prohibition against its use, and it's made available to all online players by chess.com.
wait what? an analysis tool during games? Im guessing that is an option only for paying members. Well the rich gets all the benefits (lol)- Anyaway in my book that is cheating. Why not just befriend a GM and call him before every move he surly can analyze the game for you. My oppionon, if any opponent you meet face to face would have a problem with it, its probably cheating
Tired of replying to the ignorant. It's NOT computerized assistance!!! When playing online games, click on the "details" tab. Then click on the analysis tool. Learn what you're talking about before you slander others.
Edit - actually since it's in writing it would be libel rather than slander.
If used for learning purposes, the analyze tool and other resources in Online Chess are invaluable for improving your game and extending your potential.
With Online Chess, you have the opportunity to gain better understandings of the key parts of the game. For example, during openings, you can watch some videos, do a little reading and learn the points of the moves and the overall plan. Sure, you can, and should, find out about openings in your post-game study of live games. But learning it while you play is much more valuable.
With Online Chess you can also experiment more with new knowledge. I recently played a game against a much higher rated opponent AND I was down 2 full points of material and the exchange. I eventually got a pawn 1 square away from promotion. Then I realized his rook was stuck on that column guarding my pawn. So I was able to take advantage of this to go from lost to a draw (After the post game, I realized I could have actually won).
I may have never discovered this and been able to learn how to exploit it if I was only playing live games. Now it will always be a part of my arsenal of tactics.
I would also say that saying using the analysis board does nothing for your visualization is not completely accurate.
By using the analysis board, you are able to try out differnt manuevers and tactics. Observing opponent responses and shifts in strength influence. You quickly start learning strong and weak lines. This will begin to stick in your mind and when you are playing live games, it will help you more quickly select/eliminate canidate moves.
For me, Online Chess has greatly improved my play in timed games. Probably, without Online Chess, I would still be able to improve my live play, but the rate of growth and potential are both increased because of Online Chess.
Also, correspondance play is suggested by many masters including Dan Heisman.
Tired of replying to the ignorant. It's NOT computerized assistance!!! When playing online games, click on the "details" tab. Then click on the analysis tool. Learn what you're talking about before you slander others.
Edit - actually since it's in writing it would be libel rather than slander.
Oki now I get it. I thought you had some sort of computer analyze your moves before you did them :) 
I thought you had some sort of computer analyze your moves before you did them :)
You're not the only one to make this mistake. I never used it for the first month or so that I played Online Chess because I thought it was going to suggest moves or something like that. Until I figured it out, I was setting and resetting a chessboard here on my desk.
Online games help me to to learn and test out book openings, which would not happen OTB.
If you want to become a stronger player, not using the analysis tool will not further that but neither will reying on it all the time. You have to practice seeing moves in your mind just like in OTB but my experience is that players who rely only on that, and some here boast of it, will not attain their full potential. The purpose of analysis is to be able to calculate more deeply and easily than you can using only your imagination and to see how those moves pan out. You should find that your appreciation and understanding of positions is greatly improved by using the analysis tool regularly, because it becomes second nature to be able to predict how sequences of moves may turn out. Also, when calculating extremely complex variations, moving pieces around is probably essential. Strong players investigate sequences of moves in this way and commit thr results to memory. So usually they are not actually working out so many moves over the board as you may imagine. You need to practice regularly at using only your imagination but in order to become a strong player, you need to use the analysis tool, which will aid greatly in investigating many positions with which you may be unfamiliar.
In the old days when computers first came out, I used to find that "pretending to be a computer program" helped me greatly in some types of position. Similarly now, I find that "pretending to be an online correspondence player" also helps, by focussing me on the will to look methodically at positions and not being phased by apparently higher rated opposition, because at correspondence chess, you're as strong as all the links in a sequence of moves lasting the entire game and you can play 40 perfect moves but, if on the 41st move, you fail to concentrate hard enough, then sometimes months of work is wasted in one minute. So this type of play can improve the concentration for otb play.
Thanks for all the thoughtful posts and advice. I started with 6 online games and am 5-0 with a 1658 rating. The last game is equal in the endgame and a draw has been offered. I used the analysis tool in all 6 games. In the large majority of instances it merely validated a move I was already intending to play. However, in some cases it showed that what I thought was a good move actually led to a disadvantage. In my next 6 games I will not use the analysis tool. I guess the proof will be in the pudding.
Well, I was a member here some years ago. I think I reached a rating of about 2200 or a bit more and then I sort of got fed up because I seemed to be playing too many games and sometimes I just wasn't in the mood, so I resigned them all. This time round I decided to increase my rating as fast as possible, using only the minimum number of games to do so. The first part of this was to challenge people to casual games to increase my rating to about 1500 quickly and get some games under my belt, because to join tournaments, often having played games is required. I lost one of these games by underestimating an opponent who was rated around 1660, I think, misunderstanding the nature of the position and not using the analysis tool. Since then I've competed in two tournaments and am doing quite well. I'm using the analysis tool, especially in the present tournament which included a player rated around 1900 and another at 2000, basically because I didn't think I'd beat such players without using it. In the event, it seemed that neither use the analysis tool and I won all the games easily.
It just occurred to me, as I was planning my next move in an Online Game. I usually, to some level, visualize some of my canidate moves to see if they have any immediately execuatable value.
There is nothing saying that you cannot analyze all of your canidate moves in your mind to whatever extent you want before you use the analyze button. This is probably even better as you will be getting very valuable feedback immediately that will help you adjust your thinking.
I am new to chess.com, and after a 3-0 start my online rating is well into the 1500's. I am regularly using the analysis tool during my games to study various lines of play - it's like using a second set during a correspondence game. However I'm concerned it will become a crutch. In your opinion, is relying on the analysis tool an issue? Should I be playing as if it's an OTB game and calculate variations in my head? Any advice is appreciated.