Talk to rackspace's cloud division about doing something. They seem big on working with developers and they offer really small slices. You can spawn via an AP

Talk to rackspace's cloud division about doing something. They seem big on working with developers and they offer really small slices. You can spawn via an API, so letting people on/registering and being on their own vps is fairly easy. Maybe do it where it's invite only or there's some advisory board? I don't know how you control who has access,etc.