Subject: New media tools for volunteer retention

Over the last few years, I've seen quite a few organisations adopt new media tools to enable their volunteers to work more effectively, efficiently, and collaboratively.  The most successful of these examples are groups using wiki.  One group, for example, had a very large volunteer base and very small staff.  They deployed a wiki for the volunteers to use and it quickly took off as it was the one place where they could share documents, share information, collaborate on projects, and—most importantly—they could support each other and share experiences.  It was promising to see that free, easy-to-set-up and use software like a wiki was able to profoundly improve the work and network of their volunteers.

I'm curious about the experiences other have had and what has been seen to work or not.  Thanks for your ideas!