Oh come on, the PowerShot 600 had a raw mode at least 5 years ago when people wouldn't have known what a megapixel was. I nearly bought one back then, but Olympus came out with a consumer SLR... But I digress.

My personal solution to your problem would be to set up a linux server and investigate linux software to do this. A quick google searched turned up one promising project (http://www2.primushost.com/~dcoffin/powershot/). Samba them over to the file server, run script, store on file server (or move back to the mac, if you really want).

Theoreticaly the project above is standard C code, so a real mac programer could probably get it all going on a mac, but that goes against the mac ideals of not viewing a computer as a computer. (sorry, couldn't resist, I'll stop now)

Good Luck,
Matthew