This is kinda cool. I snapped a little photo of one of my favorite restaurants from my old neighborhood in San Francisco: The Crepevine. (And it's not a very good picture! But that's okay, you'll see..) Like all my stuff on Flickr, it has a Creative Commons License associated with it.
A couple of weeks ago, I get an email from someone at Schmap, asking permission to use the photo in one of their "Schmaps", a digital travel guide (Here's how they work.) Actually, they asked me to submit my photo for consideration (but made it brain-dead easy to do so — the email linked to a form, with my photo already displayed. Asked me to confirm how'd I'd like to be attributed, then 'click' to submit. It took me 40 seconds, tops.)
Finally, weeks later, my photo has been approved for inclusion! I get a little ego-boo, Schmap gets a photo to illustrate their guide (and some goodwill from me, plus some linkey-love cause I think their service is kinda cool.)
So... kids... tag your photos up! And slap that CC license on. Fun things can come from it.