Flickr Groups are groups opened by people with the same interest and want to dedicate photos to a special theme.Personally i opened few groups such as millefiori canes, handmade israel and Polymer Clay pens.You can open your own! just do a search to check if your group does not exist.
Polymer Clay Swappers
Artistas da cerâmica plástica
The photos is from his pool -http://www.flickr.com/photos/36254253@N00/243295658/in/pool-fimo_lovers/