I love different background textures, especially grunge or abstract designs. Take a look at some of these they are great twitter backgrounds if you want to change up your twitter appearance. Or you can use them for elements within your wordpress sites. I found them on flickr under old film II by the account calebkimbrough

Film Textures

You can see the whole set on flickr and they come in different sizes, you are allowed to use them according to the creative common license rights