I am just not that big a geek that I can develop software at this level, but I would love to do some documentation to repay the people who stayed up nights making something I enjoy using.
When I worked on Lotus Notes/Domino, there was a large Web user database, supported by IBM/Lotus, naturally full-text indexed, where we could look for solutions to hairy problems. The developers also read this database and responded when they thought it was appropriate. There were fabulous solutions on there, code snippets, hints, anything you could want. Naturally I looked for questions I could answer, and also inserted anything cool that I discovered when banging my head. Yes, it was a community! I do miss it. Especially when trying to find anything on the Microsoft sites!