truely mobile hard drive?

[Jo-Jo_Fine]

Good Evening!
I do a lot (LOT) of video editing, and a increasingly, more of it on the move, from location to location.

I currently use my g4 ibook & a 250gb 3.5in portable hdd as a scratchdisk. This works well, although it is not truely mobile, as the hdd has to be plugged into a mains outlet. I'm looking for an external hard drive that takes its power from the usb/firewire drive or an external battery.
I have found a couple of enclosures from Sarotech that use 2.5 inch laptop hard drives and have li-ion batteries (more expensive models use power from laptop).

However, laptop harddrives are expensive per unit storage, and dont rev as fast as 3.5 inch drives (important in editing and capturing footage). The ideal solution would be a 3.5inch enclosure with a battery, but i'm open to suggestion. Anyone who has any insight would be dearly appreciated (possably even suggestions on getting a battery to supply a constant 9v 300ma ?)

[sna]

delete plz

[Polaris]

If you're using a G4, go to macsales.com and get one of their Mercury to Go enclosures, then get a 7.2k notebook HD. Or Seagate's 100gig 5.4k drive. Either one would then be bus-powered.