I was thumbing through Fritz Onion's new Essential ASP.NET book last night. I must say that there is a lot of good information there. He also has a really nice writing style which helps a lot, as I usually get bored quick reading technical books! : )
Anyway, the reason for this post is that he's got some cool source code and samples on his web site that I thought people would be interested in.
My favorite is the ViewState decoder. Pretty neat.