While not as cool as getting a solo exhibit in the Brooklyn Atlantic subway station, I did get my first book cover credit as a result of my Flickr habit. It's easy for your photos to end up in many places... when you give them away for free.
A couple of months ago I gave permission for a publishing company to use one of my photos, and in return a package arrived today with a copy of Cult of the Luxury Brand.
Here is the original photo of the Prada Building in Tokyo:
The complimentary copy of the book is the entirety of my payment, but heck, at $35 ($23.10 sale), it is $35 more than I have received for any of my other photos -- though the MythBusters did give me a sandwich and a burrito.