There are a number of lists of tools and strategy on using short text messaging for advocacy and other nonprofit work.
AdvoacyDev generated a list of SMS Tools.
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.