I have also been on the Chiclet's tour and would highly recommend it, but its been even longer for me since I was on that one. They actually offer tours at 4 different times during the day. I squeezed in the early one at 7am (while my buddy was still sleeping it off) and before we left the area at midmorning for our next destination. One nice thing about doing it at that un-godly hour was I was the only participant. Like Wit discovered, it makes a huge difference as, if you go at busier times or locations, the crowds can really slow you down while your itching to get going on the next cable. Another nice thing about the Chiclet tour that Wit didn't mention is you get really nice views of the Pacific in some places, which you don't always get at most of the other canopy tours.
When I went, the tour only cost about $45. We were staying at the Terraza del Pacifica, where the tour originates, so I'm sure that was the walk-in rate. I'm also sure the rates have probably gone up since then and would cost even more if you sign up in Jaco and get a package with transportation. Unfortunately, their website is history. Another website besides the ones the other resellers that Wit listed that I believe is more closely affiliated with chiclets or at least has a TON more info on it is at
http://www.jacowave.com/modules.php?name=Canopy&pa=list_pages_categories&cid=6. According to them the rack rate is $60 with possible extra charges for transportation depending on where you're coming from. So I believe that $60 price is just for walk-ins. It probably will be worth your while if you have a car to just drive out there yourself. Either way it doesn't sound like this is exactly the cheapest canopy tour around.
There is another canopy tour which IS actually on the WAY TO Jaco near San Mateo at Mahogany Park. It is by "The
ORIGINAL CANOPY TOUR®"(
http://www.canopytour.com). I don't know if they're REALLY the "original" or not but they've made legal claim to that title and are definitely at least one of the originals. They also used to be the biggest with other canopy tour operations in Rincon de Vieja, Monteverde, Quepos, Tabacon and 4 more in other countries. I believe of their CR canopy tours only their Monteverde and Mahogany Park operations remain, but they still remain one of the more reputable and professional canopy tour outfits in CR. They only have 10 platforms at Mahogany Park compared to Chiclet's 13 (not sure how the compare in terms of length, height or speed) and the price is $75 IF you book it with transportation from SJ or Jaco. HOWEVER, if you stop there on the way from SJ to Jaco, I believe their walk-in rate is only $45. I've actually been on this one too, back when it was called Iguana Park (which was quite apt as I've never seen so many iguanas in my life).
Zip-lines are a lot of fun, but they aren't the most eco-friendly things you could do. Imagine if you were a sloth (something not so hard to do for some of you) and some crazy person came flying through your house at 30 mph hooting and hollering while you were trying to sleep. Because of that speed, commotion and noise (plus the fact that you will be primarily focused on not phucking up), you probably won't see many animals while you're up there. And while it all takes place in the canopy, don't expect to learn much about that unique ecosystems while you are up there. These should be seen as an adrenaline-pumping adventure only.
For a more thoughtful approach to the rainforest canopy, you should consider a slower paced guided trip through the canopy instead of or at least in addition to the zip-line tour. The same people that brought you the Aerial Tram in Braulio Carrilo on the Atlantic side of CR now have another Aerial Tram operation on the Pacific side not too far from Jaco. You can go to
http://www.rainforestram.com/Parks/PacificCostaRica/tabid/96/Default.aspx for more info.
For more info by yours truly on zip-line tours in other parts of CR, you can also go to this thread:
http://www.costaricaticas.com/phpBB2/viewtopic.php?p=34302&highlight=chiclets#34302