After really enjoying Brian's keybinding change, so I can use IDEA style command-space to complete words in email & IRC like we complete code in IDEA - here's another keypress I've stumbled over.
Command (splat) and ` together will cycle through open windows in the
current application. Not as good as Expose, but handy nonetheless.
A brief reminder for OS X users; you can hold shift down when
minimising windows to see a nice slow UI effect which is cool though
completely pointless :).
Pressing Q while Command-Tabbing is very handy to quit applications
without switching to them - which works particularly well on virtual
desktop systems, as it avoids a desktop switch.