Build a landing page slightly explaining it with an email sign up field/submit button (like via launchrock or some other co). Invest $50-$75 or so into some ke

Build a landing page slightly explaining it with an email sign up field/submit button (like via launchrock or some other co). Invest $50-$75 or so into some keywords/ads via adwords and see if you get signups. Fastest/cheapest way to validate. If that goes well, put a full plan together with a schedule attached and go at it. Good luck!