Waaaaiiiiittttttt!!!!! Don't buy a zip drive...I'll explain in a sec. For collaboration, you need to have two of the same SCSI drives. If your going to get zip drives, I would imagin that they would be the same size. The formatt that the VS machines saves in is not compatable with computers to my knowledge...but you can download new software from the net onto your VS machine. Ok, zip drives used to be good, but now a new thing called an OBD Drive(i think thats what it is called) is either out or on its way. Its an SCSI dive that will cost $200. Disks will cost $30 each, but they are big! as in 2.1 Gb. This sounds to me like the ideal drive for VS machines.
Before I leave, a word of caution: IF you get a zip drive, make sure it is SCSI, not paralell ports or one of those which tries to decide which type of ports to use. You may sucessfully save data for a while, but if you use it for updates, your machine will be fried!