MyStickies on their own websites for a monthly fee. Something that users woiuld see and optionally can use too without an account. This would be a wonderful tool for web development companies for prototyping and letting clients post feature requests on their development site. 37 Signals talks about making the interface a spec which MyStickies could really make easy. I’m sure there are many other uses as well that I haven’t thought of. Let us know what kind of services might be useful.