I have a Concept2 as well... And I love it! I haven't had it for very long... I've just discovered indoor rowing, so right now I've just been using it when I'm hanging out watching tv instead of just sitting around... Running is my main thing... But it's great for a change of pace... I haven't checked out the Concept2 online community yet, but it looks pretty active... I know people have "races" against each other and there are all sorts of challenges that you can take part in as well... It looks like a lot of fun and definitely very motivating...
I started a thread here awhile back... "Indoor Rowing" but it didn't get much traction... which really is too bad, because I think people would really like it if they tried it... Definitely great for weight loss and a great overall body workout as well...
Sorry if I sound like a bit of a fanatic... but it really is my new "favorite" piece of cardio equipment... Well, except maybe for my treadmill workstation/computer desk... But that's a whole nother story...
Happy rowing...