If you have followed the instructions for renaming your Apple Bluetooth keyboard in OS X and it doesn’t work, the problem is actually an OS X 10.6 bug. I had the original version of OS X Snow Leopard without any patches and can confirm that the “Rename” option in System Preferences->Bluetooth does not exist. To fix, simply upgrade to the latest version of Snow Leopard (OS X 10.6.3 as of 5/11/2010) They apparently brought back the “Rename” option in a newer version of Snow Leopard.