So, the next time you’re seeing general slowness on your Mac, don’t forget to give Launch Services a kick in the pants. Guaranteed to be more effective than zapping your PRAM.
My MacBook Air was feeling slow -- especially when opening the Finder, clicking menubar items, and after waking up from sleep (at the login screen, I'd have to wait around 20 seconds for the keyboard to become responsive). It's much better thanks to Craig's tip.
You can find the Terminal command here.