Check out my blog post about something surreal that happened to me last night. 

http://derekodomchess.blogspot.com/2011/01/i-just-dropped-piece.html

Interesting observation, it's called a blunder.

Yes.  You have to play someone with a good rating the same as someone with a bad one.  I have played against players whos ratings were better than mine, and I just assumed they would not make dumb mistakes.  After checking later I realized they did and I missed it.  Never GIVE UP.  I liked your blog.

Thanks!  :)