We are a group of friends who met at university. I'm pretty close to one of the girls in the group, and we'd text casually almost every day. The rest I feel comfortable around and trust, but don't really keep close contact with. The whole group (or at least members who can make it) meet about once every month or so for lunch or dinner and 'catch up' then. We do have a group instant-messaging thing going on though.
No kidding, I have the exact same set up going on with my college friends!