Back in those days, I remember having a shell account at school, and SLIP had just come out. Someone had written a small program that would allow users to run SLIP from userland and turn a dial-up shell into a net connection.
Sounds like SLiRP :).. Most annoying thing setting those things up over non 8-bit clean lines.
I was using something similar called SLAP or somesuch -- Australian product. It worked quite well and might even be worth digging up now as an odball way of multiplexing a telnet session (eg to improve the utility of restricted access machines).
As the script kiddies got bolder and the laziness of the sysadmins and developers started to show, the shell accounts went away. More and more people started offering unlimited network access, but busy signals put a limit on that.
It's still hard to get unlimited access since it costs around 16-19c a meg wholesale in Australia.
Tried dingoblue? $27.50 unlimited if you also sign up fo rtheir long distance service (which is also cheap). Be sure to quote 100641226 when you sign up and we'll both get $40. Tim