I've used Google's suggestion feature in a similar fashion many times. When you start typing a query, a menu appears with similar, popular requests. When I'm no

I've used Google's suggestion feature in a similar fashion many times. When you start typing a query, a menu appears with similar, popular requests. When I'm not entirely sure what I'm looking for, I put in a general word, and I see what other queries are popular. This helps me find the correct term for things when I'm not sure, and I'm sure could be used to see if similar ideas to your idea have been documented before. I tried typing in 'folding car', and the list was full of different folding car parts and accessories. Executing that query would quickly reveal if anyone had toyed with the idea or blogged about the possibility. More importantly, it would show if anyone was already using the idea commercially. So I think you could specialize in this kind of searching, but it would be hard to catch up to Google. Have a large user base would be essential to the success of such a system.