Global Pattern Billboards, as i like to call it, is a technique that allows me to make patterns as 3d models, and still being very cheap in rendering resources, mostly useful for foliage.
BE SURE TO USE A GENERIC MODEL FRAME IF POSSIBLE! Foliage models will cause some issues!
http://i.imgur.com/iFpMXD7.gifv
If you're going to use it, go right ahead, but *PLEASE* give credit where credit is due!