if its not too awful you can send 10baseT half duplex over it with an acceptable packet loss
Man, that sounds almost as bad as the time (back in high school) a friend and I managed to send CATV signals down a piece of staple-gun-mounted CAT3 (phone line) spliced with some speaker cable (and further spliced with $DEITY-knows-what-else) in his mom's trailer, just so he could have cable TV in his bedroom.
It worked, tho. Probably didn't make the FCC too happy.
;D