I have used Google docs before to collaborate with a friend from another district about math stuff, but I hadn't thought to use it with my team since we always see each other. I like that we wouldn't always have to e-mail documents we create to each other, especially since my e-mail is always telling me it's running out of storage space for my stuff! It would come in handy with all the rubrics and documents we create to have a place to store that stuff where we can all easily get to it. Sometimes, one of us will "lose" a document to e-mail and have to have someone else find their copy and e-mail it again. I think this would solve that problem.
I think making quizes for students to help in reviewing concepts would be great. Some kids will like the novelty of doing a quiz on the computer.