Is you'll see at the link above, a Whike is essentially a recumbent bike with a wind sail added to it. This allows the rider to both pedal and sail down the road. It looks like a fun ride, although I have never had any experience with one.
Dave, Ned and Jamie set out from Santiago, the capital of Chile, yesterday and have started traveling north to the Atacama. You'll be able to follow their progress on Dave's Facebook page and on Twitter. Since they have just gotten underway, and intend to cover at least 1000 miles, they should be out on the road for some time. The Atacama provides plenty of great photo opportunities as well, so I expect we should see some great images and video from their journey.
The video below will give you a look at the Whike and more info on what Dave and company are up to in South America.