Les dejo una recopilación de excelentes sitios para descargar texturas.

30 Free & High-resolution paper textures via Creative Closeup


300+ Vintage Textures via Design Reviver --- incluye brushes ;)


Stock.xchng - free stock photos and great textures


111 free textures selected from stock photos via Open Source hunter


+Another 111 textures from stock photos via Open Source hunter


36 Cool free textures select from Flickr- via Abduzeedo

Free-high resolution textures: Grungy Watercolor via Bittbox


Y para cerrar,
en Flickr hay 10.300 grupos sobre texturas