I think I read somewhere (the OS X Missing Manual by David Pogue, maybe) that OS X doesn't require you to rebuild the desktop. What's up, are you getting general slowdown and generic icons where the originals should be?
Mac OS X 10.0 and Later
In Mac OS X, rebuilding the Desktop file is only applicable to the Classic environment.
- 1. Choose System Preferences from the Apple Menu.
2. Click the Classic icon.
3. Click the Advanced tab.
4. Click Rebuild Desktop.