A few textures I did for practice.

3 Rusted metal tile textures

3 Stone tile wall/floor textures

3 Concrete wall textures

These were made for use in Cube Engine 2 based games, tough they're just jpg's so you can use them in anything really.
512² resolution. Diffuse, normal, Parallax and Spec maps.
Look in the .cfg files for the 3 numbers at every texture if you want RGB values for specularity color.

*note: you can download this file from my server, as well as a high resolution version with 1024² PNG's
http://www.neuralrust.com/files/pie.tar.gz (1.8mb)
http://www.neuralrust.com/files/pie_hires.tar.gz (38mb)

Check out the comments for more history on these textures!