Rui CarmoNokia Collector is a Nokia application for the Mac with the ability to define "collections" that you can sync with your Bluetooth devices. It works with non-Nokia phones as well (I can report it working successfully with my V800), and should work with any phone that you can access via the Bluetooth File Exchange applet:
Update: There is an issue with some SonyEricsson phones containing filenames with a single quote (or at least something that looks like a single quote, in files such as Smokin'Fun.dm) - Collector 1.0 renders the filename as Smokin'Fun.dm (which indicates that it perceives that character as an apostrophe) and apparently tries to retrieve that name from the phone, sometimes crashing it. To make matters slightly worse, that particular file is firmware locked, and Collector 1.0 will try to retrieve it from the phone every time it connects...