One of my favorite small features in Visual Studio 2005 is the way you can very easily get an overview of what active tools you have running and what files you have running.
i've found this very helpful when the application's been large, spanning many projects and i've had to open up 10-20 files. Suddenly you're lost and you start either #1 closing down files or #2 looking for the one that's hiding in the tab bar of your coding window.
But there's an easier way.
Simply press CTRL+TAB, release TAB and you'll get a nice overview of files and tools you have open. Simply just use the arrow keys (while still keeping CTRL down) and locate the file you need - then release CTRL. and voila you're at that file/tool.