Camelback shortcuts: Let's say you have a class named DealCommitmentTypeBuilder. Sure, you can type the beginning and then do ctrl-space or ctrl-shift-space to get the name to pop up.

But did you know you can just type DCTB and ctrl-(shift)-space? Just type the capital letters.

Bonus tip: this works in the Ctrl-N and Ctrl-Shift-N windows as well.

What's the difference between Make and Rebuild? Answer: it's a known unknown, and the documentation is wrong: see this bug.

Change a Perfoce comment without submitting the changelist! Right-click on it and select Rename Changelist. (I've already filed a bug with IDEA to rename that command Modify Changelist.)