The latest MSDN Canada Flash newsletter announced a new Microsoft program where they are attempting to get Charities/Non-Profit groups who have technical work to be done, and match them with local IT workers who want to give back to their community. I'm not sure when it launched but there's a almost a couple hundred people signed up and at the moment 25 organizations with 10 job postings.
I'd say that even if you're not interested at least let some of your local NPOs know about this site and I know they wouldn't mind the extra help.
The concept reminds me of
http://www.nonprofitways.com/ that David Silverlight (yeah that Silverlight) helped put together. Seems like the same kind of idea.
Oh and it's not just development work being posted. Networking support is also part of the items you can select to offer your help with.