Here are just 10 active things you can do in CR, to get you started:
1) white-water rafting, as you already mentioned.
2) canopy tour, fly through the tree tops suspended on zip-lines.
3) surfing, can be done as a day trip to Playa Hermosa near Jaco or on longer trips to Guanacaste, Pavones etc.
4) bungee jumping, I'm not quite that loco yet, but if you are they have a bridge near San Ramon.
5) mountain biking, one of my favorites, imagine flying down a volcano at 65km/hr. Just be sure your brakes work.
6) mountain-climbing/hiking up Mt. Chirripo (on my to-do list).
7) sea/surf kayaking around Manuel Antonio.
8 ) "canyoning", also near Quepos, the newest adventure travel sport.
9) horseback riding.
10) windsurfing on Lake Arenal, one of the premier spots for this in the world (not a place for beginners like me though).
I've tried most of these and will provide more details on request. I could list more but this should get you started. One sport I didn't mention is scuba, which is available but which CR is not really known for (except for a long trip out to Isla de Coco)
OH yeah, I forgot to include mongering, although looking around here I'm not so sure how fit one has to be to do it
![Twisted Evil :twisted:](./images/smilies/icon_twisted.gif)