I have a PowerMac G4 at my office running Leopard Server that I'd like to be able to access remotely. Normally, I'd just use VNC / SSH, but it's behind a router that I don't have admin access over (it's in the office next door and we're in a piggybacking agreement, I just don't feel like asking him to forward ports, etc). I think "Back To My Mac" generally can take care of this, but it's going away and you can't subscribe to MobileMe anymore anyhow.
Is there any software out there that can either UPnP it's way around this situation or somehow create an outbound connection? I suppose it being a PowerPC throws a wrench into the plan also.