I run a company that among other things, works with mid to early stage startups (as in, some folks with an idea). We help them build the product (design, development), launch it and do marketing. My email is in my profile if you have any questions, etc.
I recommend nailing down exactly what you think an MVP should look like and iterating on early customer feedback.
It's important to stress that we are there to help startups augment their teams at later stages, but by no means can we replace the culture and passion of a dedicated team working night and day to make your dreams come true.
We can build you something fantastic, help you grow a user base, but at the end of the day the road to most effective profitability and vision is in the hands of the founder.
I really agree with the sentiment of audition projects. The interviews I have enjoyed the most all involved some sort of take-home project, although I have never been paid for one. On that note, how expensive does it become for a startup to dole out many interview projects across a wide range of candidates? I think a better strategy would be to conduct preliminary interviews and then based on some granularity, assign projects. One more issue I have with take home projects is that it is not always possible to tell who did the work. When it comes to interviews at startups I doubt that there would be much cheating, but for large companies where candidates are more easily able to slip through the cracks, I image this may present an issue. Can anyone speak to this experience?