There is rarely an existing solution for your specific needs. And sometimes, at some point it becomes more work to tweak an existing thing into what you want it to be, than just do it from scratch. Yes, you can't always know that beforehand, but that doesn't mean it's always safer to err on the side of taking something off the shelve.

That said, seeing how the images are creative commons licensed, it would still make sense to put them on flickr, too :P The more, the merrier.