If you are running Leopard and have updated to Safari 3.1, you may have problems syncing your bookmarks to other sources such as .Mac, your iPhone, or your iPod Touch. If this is happening to you, there's a fairly easy fix.

To start, you need to quit Safari (Safari -> Quit Safari in the menu bar). Then open a terminal window (Applications -> Terminal) and copy in the following line on the terminal command line:

defaults delete com.apple.safari RegisteredSafariSyncClient

Once you enter this line into the terminal, it should fix the bookmarking syncing problem in Safari.