It is a great little idea- that I would give away if it meant that it would be used. I do want to be in a position where I am able to take credit.
What do I do?<p>Should I build a prototype? And then just start knocking on doors? Cold-emailing founders?<p>This is a complementary idea-- it would be something that companies like: SCVNGR, 4Square, Facebook and even Color.com will one day adopt to improve service for their users (and add value in their partnerships).
Quoting Paul Graham "ideas are worthless" (ref: <a href="http://www.paulgraham.com/ideas.html" rel="nofollow">http://www.paulgraham.com/ideas.html</a>)<p>I would suggest cracking out a prototype and go from there - "ideas are 1% inspiration and 99% perspiration".