I talked to another LW person who said he loves the Bryce textures as well and he makes a 2d plane, loads the texture, renders, takes a screen shot, then goes to Photoshop to make it tileable. One way to make a tileable texture is load your image in PS, make the canvas size large enough to put 4 of your images on it. Put your image in the upper left corner, copy it and flip it horizontal and place it just to the right of the first image. That should give you texture across the top half of your resized canvas. Flatten the layers. Copy and flip inverted and move to the bottom half of your canvas. Now you should have a texture that is seamless.