My group of friends shifts quite a bit nowerdays, mostly because I study and live far away from where I come from. I still go "home" almost every weekend. I normally see someone every weekend. Not the same person, though, sorta rotating. I try to get as many of them as possible into a room to maximise friend-exposure. Magic: The Gathering and D&D work quite well for that.
The people in the town I study in are... well, I'd call some of them friends, even if they might not call me a friend. I see them every few days, mostly because they are the best friends of my flatmate. We all get along, but we don't do all that much together.
And then there is obviously my flatmate, who I'd obviously call a friend. I see her pretty much five days a week, and once a week we watch TV together.