UV mapping tutorial ?

[MALAISE]

Hello dear All

Would it be possible to get some tutorial on mapping non geometrical forms.
I mean, I saw on a old post, a rock texturized ( may be by SOLO ).
Some explanation would be appreciated. I've done a small tutorial about uvtool from Whaat..http://www.sketchucation.com/forums/scf/viewtopic.php?f=18&t=11979
but others techniques could be shown..

Thanks for any post.

MALAISE