Thanks. I am working on something new actually, but this time with a cofounder. We're taking the opposite approach - find the market, customer development, then build something. I think both having a cofounder and taking this approach make a lot of sense if you are serious about the project. When I started blaster.fm, I wasn't.
I think having customers early is key to creating a sustainable project. A good co-founder is also priceless. It sounds to me like you're on the right track, I wish you luck in whatever you do next.