Update: Apparently this has been available since VS2005. Who knew? Other than the people that commented, of course. Certainly not me. :)
Update #2: So, the "organize usings" menu item that I happened to show in the screenshot alphabetizes the using statements. Also very nice, although I'd like it better if it didn't remove the line breaks I put between groupings. Still, nice. You can also remove unused using statements. Here's the menu:
Jon Flanders showed this to me the other day. In Visual Studio 2008, if you've just added a class for which you haven't yet added the corresponding using statement to bring the namespace into scope, you can hit control-dot, and up pops the following menu:
And sure it enough it pops a "using System.Collections;" in up at the top of the file. Very nice. Better still if it would put it in alphabetical order, but I seem to recall that the order of using statements is significant when Linq is in play, so maybe they couldn't do that.
You can also access it via the right-click menu: