LoreSoft.com
I feel like I've hit .net developer's gold.
I was searching for a spell checking component and came across this site (with the help of Don Smith). Not only is there a spell checker component there (which looks pretty good at first glance) but there are a bunch of other useful tools ranging from a Windows API file search wrapper to web access for Visual SourceSafe and Draco.NET.
Good stuff.
P.S. I'm hoping to add spell checking and a couple of other items to PostXING. If you'd like to snag a copy, you can find the latest release here.