Reality Factory

Texture Desk by Spectralogue is a must get tool. It lets you preview textures in 3D and rotate it.
I stumbled across it whilst searching for textures.
Here's the address: http://www.spectralogue.com/texturedesk/

That's a great program indeed. Though you didn't mention its best feature: tiling. You can make it tile your texture, for example, 3 times vertically and 4 times horizontally. It's a very good tool for creating seamless textures.