TCP is the preferred method. It's quicker, more reliable and not a toll call for most.
Floppy disks are cheap and easy, after all.
Adults and kids also email themselves files as attachments and then go home, log in and download them. We have opened this up for students, faculty and now parents as others have. It does make some extra work, but not as much as I thought. I'll answer some simple questions, but with major problems, they have to pursue that with Softarc. We provide them with the install disks, the settings files for modem or TCP, a copy of the Reference card, and an instructions file.