I’ve been using a service called Get Satisfaction to provide support to users of our iPhoneMiles service. It’s a community site that lets people discuss or ask questions about our service, and lets me answer them on there. It’s an easy way to set up a public support area, and it’s certainly cut down on the questions I get in email!
I’m also impressed by videos on their blog from the Customer Service is the New Marketing Summit. Marketing is a Tax You Pay for Being Unremarkable by Robert Stephens of The Geek Squad is great, no matter what your industry.