Just for me, I go on a REALLY long walk every morning, and now that the weather is getting nice, will probably go for a cycle along the water with my ipod turned on in the afternoon. I find that being out and about, and interacting with people as much as possible does the trick for me.
But that's all very well for ME to say, as I am now permanently home, and don't have to deal with the stress of a daily job; plus I go see my therapist once a week to tell her all my problems.
As for a bipolar support group - I never entertained the idea of that, and I am not sure that I would necessarily be comfortable attending a group so defined. Isn't it better to surround yourself with normal people to keep yourself calm, rather than a group of people who may like you get manic or depressed, and that in itself might set off similar feelings within you? I don't know the answer to that question; just that I never thought of that concept.