Colorful crates wash ashore Tiki Farm
These may look like colored blocks from a puzzle game, but they're actually decorative crates that Playdom's released for their Facebook island farming simulation game, Tiki Farm. The crates have their own tab at the in-game store, costs 50 shells each (shells are what passes for coins in this game), and while they're not stackable, they make good dividers (almost like the colorful Hay Bales in FarmVille).
Another unexpected use for the crates, as evidenced by the growing number of in-game fanart showcased on Games.com's FarmVille Pic of the Day, is to tile them on your fields to make pixelated artwork for some pretty amazing results.
A sizable segment of Restauarant City gamers tend to play around like this as well, just check out this YouTube video of a user recreating Hello Kitty on the floor of her restaurant using various colored items and floor tiles.