Well, I setup my friend's PC to share his dialup connection with his Xbox. We tested both R63 games and GR2. Surprisingly, both R63 games played decently. We played an entire board and there didn't seem to be any significant lag. GR2, however, did NOT play. I saw the host's game and tried to join it. It would attempt to join and then after a while I would get the message "The session is no longer available". Oh well. At least the R63 games worked. I'm sure a handful of other games must work over dialup.