I'm not sure if this has been discussed, but Live Mesh Remote Desktop works great for accessing my MacBook Pro, which has XP running under Parallels. Even though you can't execute OS X programs (obviously), you can access all the files in the OS X file system, as well as the Windows file system. They show up in Windows Explorer under Parallels in a .Mac folder, where they can be copied and pasted onto your local machine using Live Mesh. Of course, you can also execute Windows programs that are installed on your Parallels drive.
This is very useful - I can now access my entire MacBook Pro filesystem on my laptop that's sitting on my desk at home, while I'm working anywhere. This means you don't need to synchronize the entire file system - you can just grab files as needed.
