LawBidding.com is a free service that allows you to bid on legal projects submitted by potential clients that need help. Once you find a case that you want to work on, just fill in the questionnaire. Potential clients review the bids and can then make a selection.
Keep in mind that this is a new, free service and does not have a large list of open projects. This will likely change as more clients and attorneys use the service. Right now, it doesn't cost anything and doesn't take up a lot of your time to try it out and who knows, you might be able to pick up a few small matters here and there.