Mac software to recover deleted files from mobile phone?

Hope this is the right place to ask this... I'm desperate to recover some 'deleted' files on my (HTC) phone, presuming it might somehow be possible via the Mac.

I'm able to see the 'live' files on the phone via the Mac finder but can't see the deleted items there. Have visited lots of links claiming that this can be done, but cannot nail down a way to actually do it!

I'm guessing (just based on my experience with my Droid Incredible) that the Mac mounts the Android phone as a Flash drive. If that's true, you should be able to use a deleted files recovery tool, but those will generally cost you a few bucks.

Data Rescue seems to be a popular package, but it certainly isn't cheap:

Mac Data Rescue, Mac Disk Recovery, Macintosh File Recovery - Prosofteng.com