There are a number of lists of tools and strategy on using short text messaging for advocacy and other nonprofit work.
On Mobile Active, we are compiling resources and articles on using SMS for advocacy. Aspiration and Green Media Toolshed are hosting the site in conjunction with a strategy meeting of activists in Toronto in September 2005.
It includes a rich set of resources, articles, case studies, and tools.
Others? We'd love to hear from you on other resources on using SMS for social change.