There are a number of ways to create textures in photoshop (without 3rd party applications). You can bump map, in pshop, for one. Filters>Renders>Lighting Effects gives you ample opportunities to create a texture over any image using Alpha or RGB channels. There is also the quick way, but using the Texturizer, as well as compositing layers with blending. I'm not creating a tutorial here, just wanted to drop an FYI.