umbrella tree bonsai?

i posted a picture with the same subject in photos
http://davesgarden.com/showthread/photos/14568.html

is it an umbrella tree? how would i go about making a bonsai from a rock and not a pot?

us the rock as a pot. digg a big hole in the block and drill a small hole down to the ground (bottom) of the stone.
water must can live verry well.

(but must it be this kind of tree?) ;>(
bert

thanks bert
no it doesn't have to be this tree. i wasn't sure what kind of tree it is.
do you know how to do the ones where they're hanging onto the rock?
thanks