Have you ever wanted to walk away from your Mac and lock your screen, without waiting for the screensaver to kick in? For some reason, there's no menu item on the Apple menu to do this. Well, I wanted to finally figure this out, and an old MacWorld article has some great tips that use OS X and don't require installing any software. And What Do I Know has another interesting one.
Personally, I went with adding the "ScreenSaveEngine" application to my dock. And with a little training, Quicksilver is trained now, too.
Any other suggestions?