Here's a recreational activity I recently devised. It's pretty simple. Someone (in this case me) posts a tile. The first person to say which tileset it came from then posts a tile of their own. Etc. If people aren't getting it, hints and/or additional tiles are acceptable, or you can start over.
To be fair, please don't post things like solid black squares or generic destruct blocks which are in lots of tilesets. Go for something unique. And probably avoid stuff that isn't even on J2O.

(If this should be in Forum Games instead, someone can move it... I just figure this is the forum where people pay attention to tilesets.)