Just to reiterate what a couple people have already alluded to: the BC Law running club is very, very sweet. It is probably the most well-run student organization I've ever encountered. Not only are there multiple group runs/workouts scheduled every day, but it also provides access to about 1 race per month (weather permitting), in some pretty cool places like Cape Cod, Maine, etc.
For example, in October, we took a trip up to Stowe, VT for a training weekend. Some people just went up to booze/soak up the mountain air, but some of the more dedicated took a 20 mile bike ride up to Smuggler's Notch, followed it with a 5k run over the river and through the woods (literally), then everyone capped the day off with hike.
Likewise, we entered 4 relay teams in the Cape Cod Marathon in November, which was also a lot of fun. The president of the club is really knowledgable about all things running/working out (he's a mutliple Ironman finisher), and the personal gains made by people in the club reflect it. Some girl went from not having run more then 5 miles to running a half-marathon at a 9 min pace or something. Overall, probably the best people I've encountered at BC Law are in the running club, so I definitely suggest signing up