Even though wikis are easy to use, Google Docs are just as easy, but I only use them on a minimal basis. With the students, I think Wikispaces is the best because they do not need an email account to log in. However, I have used Google Docs within my professional organizations. With many of us scattered around the country, collaborating is easy! I can't help but wish this was around when I was in college...it definitely would make group projects much easier to get done!