Time Machine on two drives at diff. locations

is it possible to get two hard drives, (lets just say FW400 750gb for the sake of the discussion).

Put one of them at home and set up time machine, then put the second at work and 'change disk' in time machine prefs to the new one, and everytime you change locations just tell it to change disks to the one matching your location - and have both disks being full Time Machine backups without having to 'do a full from scratch backup' every time?

Then it seems like you could use something like MarcoPolo to have it automatically change those preferences based on which networks it sees or something, so that it is just time machining automatically and properly no matter which location you are at.....would this work?