A running list of the utilities and preference panes that I find that can be replaced by Quicksilver.

• LockTight
  A Preference Pane that can set up a hotkey to lock the Mac, basically by starting the screen saver and requiring a password to wake it up. In Quicksilver, a trigger can accomplish the same thing.

• Jumpcut
  An application that keeps a history for the clipboard, allowing you to go back and re-paste things that you used before, even if you’ve used the clipboard for other c-n-p since then. Quicksilver’s Clipboard History plugin accomplishes the same thing.

• iClip
  Another clipboard history app. This one will set you back US$29. While it’s certainly more stylish than Quicksilver’s Clipboard History, it’s functionally equivalent, and the thirty bucks can stay in your pocket.

(for you poor Windows users, you might want to look at Stuff that Powerpro replaces for a similar list.)