Flickrcrete utilizes the flickr api and thus requires an api key to use. You can get this at www.flickr.com. Flickrcrete will display your flickr photostream or a given public photo set as square thumbnails. You can then display your images in a lightbox or simply link back to the orininal photo on flickr.
I saw someone else take this approach and I liked it so:
Flickrcrete is free for personal use. Please send me a private message to request a license. However, if you are going to use flickrcrete for commercial use or you are building for a client please pay the $15.00 for the add-on. This helps both Concrete5 and me out. :)
You should not display more than 30 Flickr user photos per page in your application or use an unreasonable amount of bandwidth. ***