Look at -- how do I let people in? How do I let people contribute? How do I lower barriers for participation in everything the organization does? Wikipedia hired its first paid staff member when there were already 1/2 million articles. A staff of 16 people facilitate the work of 100,000 volunteers globally. Key function of staff is enabling people to help.
Lesson #1: Languages matter.
Less than 25% of Wikipedia articles are in English. Supporting languages is harder than you think! It takes commitment early on. Being a multi-lingual organization is something you have to constantly work on and make happen
Lesson #2: Open your code.
Your cause is not proprietary your tools shouldn't be either. Release what you have, even if it sucks. Investigate affero gpl (created specifically for web services).
Lesson #3: Open your online work.
Use wikis :) Give people access to your version control system. Give people access to your servers and database :)
Lesson #4: Empower the grass-roots.
Have face-to-face meetings and encourage local chapters.
Lesson $5: Use open tools.
Not just for the work facing the users... but for the internal work of the organization, too. Share experiences with other organizations. Report bugs. Write or commission code. See FLOSS-Exchange. See also freshmeat.net.
Wikipedia as a social tool. Eric's tips... use and learn. No, really. Use and learn. Play by the rules: free content, open source.
Check out our MaintainIT blog, too, where I'll take some of the ideas from today and consider them some more (while wearing my librarian hat).