I've been subscribed to the GotDotNet User Samples feed for several weeks now and it's great because you get to see some really cool tools come in.  I love playing with the new stuff and pulling the code apart to get inspiration for how to implement features on new projects.

The latest tool that I've seen is RegexLibrarian.  It's neat because it allows you to easily build an assembly of your favourite, most useful utility patterns for re-use.  The code is well commented (C# using XmlComments) and has some interesting Xml related code for the bag of tricks.