This thread reminds me of a cool shareware I've tried several years ago (somewhen in the last millenium). It was called Infinity Textures and offered a lot of generators, filters, presets and, most importantly, seamless drawing tools (you were working on a tiled, infinite canvas) so you could give the texture some sort of shape before working with filters.
I would recommend Infinity Textures to anyone but I can't - it has been renamed to
TextureMaker . TextureMaker seems to offer some amazing features - extracting a texture from a photo while adjusting perspective and removing illumination gradients, generating seamless animated textures using particle systems, preview textures mapped onto 3D models, a terrain renderer similar to good old
TerraGen (something you can definitely waste your time with
)...
So if you're looking for a professional texture generator / editor with some additional time-saving and time-wasting
features this seems to be worth a try (30€ for private use, 65€ for commercial use, and there's a feature-limited freeware, too).