How solid of an opening is the King's indian attack?  I was thinking of playing it myself, but I didn't know if should stick to something like the Ruy Lopez.

It is sound and probably better than the Ruy which is completely overrated.

I have played the kings indian attack quite often and found it to be very useful. HOwever it does have its major weaknesses. If you castle into it then your opponent can break his kingside pawn structure to attack your pawn on g3, I have noticed that a heavy pawn attack on the kingside after casteling is frustrating to deal with. Be prepared to sac a minor piece if this happens. 

Aside form the that if your opponent does castle queenside in order to prepare the pawn attack most of your pieces are geared to attack that direction anyway. 

 Here is a game where Fischer played the KIA will success.

You can also look at the Barzca Opening.  It can easily tranpose into KIA, or French.

http://en.wikipedia.org/wiki/King%27s_Indian_Attack

thanks for all your responses.  I have noticed the same thing loki when I castle short, should i push h3?

This is completely wrong, and poor advice, IMO.

The KIA is sound.  Tricky to play, and not recommended for beginners, though.  You're better off sticking with regular e4 openings for the time being.

I agree, KIA is as sound as it gets but it is not for everybody. ou need to be "That" kind of player to play it. As for the Lopez, Kasparov himself said that whether you play it or not it is importand you learn the positions arising from it as they are some of the most fundamental in chess strategy.

Why do you want to play the KIA? If it’s because, as many players think, you can just play the same opening moves against anything your opponent does, then it’s a bad idea. It requires as much study as the Ruy Lopez or any other opening. This is because to play it correctly you have to adapt a different strategy against each Black setup, and he has a lot…French, Sicilian, QG, K-Indian, etc., etc. type Black setups all require a different White strategy.

I’ve played it. It’s solid and offers attacking chances but no more so than any other good opening.

The opening is sound, but I would not recommend it for someone at your level. The KIA often leads to a closed position, playing in closed games all the time can inhibit your tactical development. Stick with simple openings like the Italian game or scotch that lead to open positions. when your rating is up over 1700~ then consider the KIA.

Actually, I began playing chess with a lot of d pawn opening structures so I have seen a lot of "closed" positions.  However, you are correct in saying that it does inhibit tactical development because I have lost several games in recent months because of not seeing tactics.  I have since tried to correct that problem by doing tactics on the chess tempo website and reading lev alburt's pocket chess training.  My tactical eye has sharpened greatly, but I am still underdeveloped in that area of my game.

Ok, Ive tried the King's Indian and I do like it.  It seems to suit me, but I am still ready to break it out in a tourny just yet.

I'm about a 1200 player (recently started playing people in the 1300's) and have seen much success with the KIA.  It's probably the only opening I use as white now.  Do you guys recommend any other opening for me to explore, based on my liking of KIA?  I do like the challenge of closed games but feel that I need more development in open games.