Cool Sidebar Gadgets
Check out my Office 2007 Recent documents sidebar gadget:
I downloaded this from the MSWindowsLiveGallery Profile Author's page at https://gallery.live.com/Author.aspx?a=470e25d8-e8d0-4100-924b-abf9f4cf777d&l=1
Also, of note is the Live Search gadget.
And don't forget the MSDN Gadget