I stumbled upon a great workspace at GotDotNet: Visual Studio Core Community Powertoys. Here you can find some pretty neat powertoys for the Visual Studio IDE. For example:

Go Back Visual Studio Add-In
The Go Back Add-in provides a Navigate Backward functionality that is different than the normal Navigate Backward functionality. (Which does some neat things like close a file if you happened to have opened it while navigating forward)

VSMouseBindings
You have a 5 button mouse, why not be able to assign all five mouse buttons to commands within visual studio?

Read Blogs Without Leaving Visual Studio
This open source plugin ships as part of SharpTools 2.0 and is a full-featured RSS / Blog aggregator which integrates into the familiar dockable panes of the Visual Studio.NET IDE.

So, are you interested in using (or making!) Visual Studio Add-Ins? Check out the Visual Studio Core Community Powertoys workspace at GotDotNet.