Ask HN: How to get computer tech support clients?

Are there any popular websites for offering freelance tech support? I have a couple clients who I help over the phone with computer / phone related issues, and I would love to have my schedule booked with clients. I'm just not sure where to find more. I've posted ads on Craigslist, but I've never had success. The irony is that many of the people who need my help don't know how to or can't get to CL.

I could also go door to door giving out a business card, but it'd be nice if there was a site where I could offer my services and get clients quickly.