In that same dial-up period at University I also set up a way that I could get files off my home computer while on campus.
I left my computer on all the time with the modem hooked up. From campus I'd call my home phone number and after a few rings my computer would answer. I'd written an ugly bash script that relied on a nifty program (whose name I forget) that told you which DTMF tones your modem was hearing. The bash script was a simple voicemail menu that, if I entered my super-secret number code, would:
Then I could FTP whatever I needed off my computer. When I was done I'd enter some kind of command that hung up the dial-in connection.
It took me quite a while to build and test this system and I only recall really having to use it once or twice.