1.) Facebook Fan page/surveys – Use a fan page to generate enough followiers to prove the opportunity.
2.) YouTube – do a video demonstration and use social media to drive traffic and "likes/comments"
3.) Kickstarter.com – Raise money and show how well received the product is at the same time.
4.) Google Insights – these analytics are a powerful way to see what similar items are doing in the market proving a demand for your solution.