I actually have two favorite keyboard shortcuts that I use all the time.
When defining a class signature that will implement an interface or abstract class (class something : ISomethingElse), you can press SHIFT - ALT - F10 then ENTER after you populate the signature and it will populate the needed method signatures for you. I know it sounds a bit hairy, but you get used to it pretty quickly.
My second favorite is CTRL - TAB to cycle through the open tabs in the IDE. This also works for any tab control.