A package manager for the web. nothing more nothing less. From Twitter OSS.
If your a Mint.com and Mac user this is a nice little app that keeps you on top of your finances.
Optimal Layout, this is really nice for finally taking full control of your screen realestate.
Widget Context is a nice widget I've now used a few times to help define where widgets should be placed.
This is a really sweet proof of concept.
Great look back By Chris Coyier at techniques for doing image replacement via CSS.
Ever see minified JS and want to see what it looks like formatted. yup there's a web app for that. JSBeautifier.org