I talked the guys who make Genetica into enabling it to generate seamless 3D volume textures.  Genetica 3.0, when it's released, will have this capability.  This is an excellent way to create cool looking assets for your pixel shaders, which can be mixed etc. to create a really cool looking game.  Given the tight licensing requirements of Allegorithmic, this is a much cheaper way for the poor man (like me :) to get a similar result.

http://www.spiralforums.biz/index.php?showtopic=8164

http://www.spiralgraphics.biz/genetica/gen3announce.htm