A really interesting Facebook powered campaign organised by the people at Globe for Darfur. A while back they created a group called 16 Days of Action and started recruiting people to join it. The aim of the group was to get members to engage in 16 forms of activism over 16 days, such as sending a video for Darfur, posting a blog entry about the crisis, and phoning your political representatives.
What is interesting about this campaign is that it seems to be wholly Facebook based (the only url on the press release launching it is the Facebook address). I reckon this can be interpreted in two ways (which aren't mutually exclusive). It can certainly be seen as an inspired or powerful use of social networking to cheaply and quickly organise a campaign. But additionally, it has to be asked whether it excludes people who don't use Facebook from participating - and in the process, overlooks potential supporters.