@Redgirlsays, you mentioned Campfire, but I'm curious if you and your co-founders use other tools to try to make things seem "closer?"
Lots of emailing and instant messaging, occasional Skype chats, and sharing photos and videos (generally work related, occasionally random or just for fun). Dropbox accounts also make it easy to share larger files, but that's less a 'closer' feeling than just making things more accessible and connected.