With the release of the recent Steam Community, there is now an even easier way to keep in touch with all your fellow Interlopers members.
If you haven't done so already, head over to the Steam Community website and sort yourself out a profile page
If you want to join the Interlopers group then head over to this thread and post your profile link, and some kind-hearted individual will chuck you an invite. By keeping it invite only the stats remain for the whole group, allowing you to be nosey and see what everyone is playing.
Don't forget it also comes with a fancy IRC-like chat room, so join in.