Same here... I've got enough disks to last the apocalypse and have installed internal drives in any system that would take one. (Except the MDD as the Zip faceplate is pure unobtainium, so that one has a Firewire Zip250.) I even have a Zip750 and a SuperDisk drive on the system at work; the latter serving mostly as a USB floppy drive.
BTW, in case you didn't know... the mechanism in the Pismo expansion bay Zip is common across expansion bay disks and electrically and physically compatible between Zip100 and Zip250. I actually "upgraded" mine from a Zip100 to a Zip250 by using the actual drive mechanism from a Dell C-series Zip250.