After long time of scratching paper, covering it with ink and scrupulous digitizing, folks from Pixelbuddha team are gladly giving away 9 hand-drawn grunge textures (both original & halftone variants) in PNG and vector EPS formats.
Knowledge is the light in the darkness of ignorance. These flat icons work the same: they highlight your designs in a huge flow of the other ones. Especially, when you can get them for free!