Of all the hundreds of tags you can see in our mashup tag cloud, the second most popular behind "mapping" is "photo". How popular? As of now there are over 200 photo-related mashups listed at ProgammableWeb -- 202 by today's count. Also, you may not be aware that there are 14 photo-related APIs. The vast majority of the photo mashups listed, about 80 percent, use the terrific Flickr API. Others mashups have been built with the Fotolia, ImageLoop, and Smugmug APIs. A number of the all-time most popular mashups are photo mashups. For example, one of the all-time Top Ten includes Flickr Sudoku, that lets you play sudoku puzzles using numbers from Flickr images.
Speaking of diversions, Spell With Flickr lets you interactively create ransom-like words using Flickr photos.
And, if you want to program your own Flickr mashups, last fall we looked at 3 how-to books on Flickr mashups, the newest of which, Flickr Mashups by David A. Wilkinson, just hit the stores two weeks ago. We'll have more on this and other mashup books coming-soon.