I just found this cool site that can take the serial number of your Apple hardware [computer, iPod, etc] and tell you more about the item — the Apple stock number, which factory it was assembled in, the week it was made, and other little factoids.

Handy in a pinch: I was trying to diagnose why a friend’s MacBook wouldn’t boot when she put 4GB of RAM in it … turns out that her model only supported up to 2GB, and she had mistakenly thought it could take 4GB.

Remember that you can find the serial number by clicking a couple times on the version number text underneath “Mac OS X” in the About This Mac dialog, or simply in the Hardware Overview pane of the System Profiler app.