Can anybody suggest the best way to go about finding software development jobs within charitable organisations?
This comes from an experienced developer who dreams of working for a company he actually believes in :)
The most obvious answer would be, of course, to check job listings for some of the larger charities. But how about the large number of smaller charities out there? Where would they advertise?

charitytag; check out the other threads using this tag, especially Are there opportunities working as full-time paid programmer for Non-profit organizations. – Péter Török May 26 '11 at 8:52