Wow, 2 out of 5 people responding to this are in the Stony Brook area? I so rarely see people riding in the area. I'm usually out there (riding somewhere between Nissequogue River Rd and... Orient Point, I guess) at least two weekends a month. Lately I've been keeping the rides to loops in the Nissequoge/Stony Brook/Port Jeff area. I guess that I ride at odd times, though. You'd have to pay me to wake me up before 7 AM, and even that doesn't usually work. That area is beautiful right now with the change of seasons.
I went to SBU for undergrad. Now I live in the city, but my parents live in the area and I visit often (not sure if it is more for the riding or for the family). I appreciate the roads much more now than I did when I lived there.
I've gone on a few B-paced and C-paced rides with the Massapequa Park Bike Club. The folks on those rides do tend to be older (30's and up), but I've always had a good time. They got a calendar of upcoming rides at their website for anybody looking to do group rides: http://www.massparkbikeclub.org
I've also ventured further west and done a few rides with the 5-Borough Bike Club in New York City: http://www.5bbc.org Also older folks, but always good company.
Both clubs are year-round, so right now is the season of crazies like me who ride all bundled up in our winter gear, LOL.
For me, company is always welcome on a ride-- with the clubs or arrange by PM.