The new version support MAC and I have not tested it yet as I am waiting for a spare phone on what I can do my testing.

The last I heard it only worked on Leopard but I am hoping for support for Tiger as there are not allot of people that has update to Leopard yet.

Here is the link and have a read through the READ ME.

http://rapidshare.com/files/92459629/ZiPhoneOSX-2.3b.tbz

Enjoy