I'm curious if there is a list of publicly playable dfterm2 servers you can telnet into somewhere to play Dwarf Fortress. I have seen a few servers mentioned on Steam Community sites dedicated to Dwarf Fortress, and one mentioned in the bay12 thread for DF, but none of them seem to be online (as of 2011-09-29).
As of February 25th, 2012, "Carnes" from the Bay 12 Games forum made a small PHP script to check for the online status of known dfterm2 servers. He prepopulated it with a few servers from the dfterm2 thread and there are 3 currently online (4 total) for me at the moment.
Needless to say, if you run a public dfterm2 server yourself you should register it so that others can keep track of the servers and their status.