Here's another shortcut that everyone should learn. It's a godsend if you're switching repeatedly back and forth between two windows, and useful even if you aren't.
1: Alt-Tab
Pressing Alt-Tab will allow you to switch windows to the most recently used window. If you continue to hold down Alt after releasing the Tab key, the window switcher will remain open and allow you to select any other window as well.
If that sounds confusing, try it out, and it will become clear immediately. (Mac OS X users: Use Command-Tab instead of Alt-Tab.)
The behavior of Alt-Tab is actually a lot more complex than it looks--if you're interested in the details, see the
Wikipedia article. But the main thing you should remember is that it lets you easily toggle between two windows. Next time you have to copy and paste text several times between windows, try pressing Alt-Tab instead of clicking each of the windows in turn, and keep your hands off the mouse!
2: Similar Shortcuts
On Windows Vista and 7, Windows-Tab (the Windows key is often labeled with a flag icon) will do roughly the same thing, but display a fancy Rolodex-style preview of the window. On earlier versions of Windows, pressing Windows-Tab will select each program on the taskbar in turn; you can press Enter to select one.
Alt-Tab is really handy in keyboard macros, which I'll probably write an article about later on.