First, thanks for your aswer.

Sorry but I didn't find this sandstone you mentioned inside the texturizer filter in CS3. But I've been thinking that I can get it with 2 bumps maps, one based in clouds and the other with another bump texture or may be bumping noise?..., in 3d is quite simple using bumps, I'm sure in Photoshop has to be easy as well.

I also made a question in my first post about scaling clouds, since I think it could be used to make the mountains combined maybe with some noise...

By the way could you please tell me the way to make the bump map in photoshop, I've been checking with the channels but not sure exactly the way they work, or if you know a good tutorial to do it... I've been reading with bevel but is quite more complicated and harder to remember than with channels.