I did a jigsaw activity where students in groups number off and then broke up into their numbered groups to do research on a biome... these numbered groups built together a wiki page for their biome... they became the experts on that particular biome. When they returned to their original groups the Wiki pages became the textbook for the other group members to use to learn about the biomes they were not experts in.
They then used this information as a group to build a brochure for a World Biome Tour, listing information that would help sell each biome... they also were to include information for the tourists on the type of clothing or equipment that was needed to adapt to each biome.
This was done in a high school and some work was done together as they worked in a lab but with the wiki, they could have done this entirely online.
Have fun! We did!
We had the idea of making the wiki resource available to teachers of younger students as a resource but haven't had any takers yet.