Alright I'm about to jump at a MBP 3.06 17" and I'd like some feed back from you guys as to what you are doing with your single FW800 port. I'll probably remove the dvd drive and either add a ssd for boot or another 500gb7.2k drive (want to know more google maxconnect). What are people doing for scheduled backups? USB! express card (sonnet Pro800) with usb power adapter? esata with a usb power adapter.
I used MBPs for several years as my main computer, the latest having FW800 as does a Mini I'm currently using. Much faster than 400. The 800 port is also backward compatible with 400 devices.
For backup I use an OWC Mercury 800 double drive box and a Thermaltake USB drive dock, using SuperDuper to make bootable backups on one partition and keep image archives on another. I have two drives for the dock which get rotated between the dock and a safe deposit box, and the backups are kept powered off when not being copied to.
A cheap external FW drive has also worked well as a scratch disc for Photoshop. FW card readers are also available.