Here's a handy trick for whipping C# using declarations into shape. Visual Studio 2008 will remove unused using declarations, or sort them, or both in one shot. Here's how.

In Visual Studio 2008, open a .cs file. Right-click anywhere in the block of using declarations at the top of the file and select Organize Usings. Now you can select Remove Unused Usings, Sort Usings, or Remove and Sort which does both.