Dynamic function - or how to build a tree, branch after branch

Hi,

i often wondered if it was possible to put variable functions into grasshopper.

I wanted to build a random tree! 

For example if you add a random point in space. Than you add another one based on the parameters of the first one.

is it possible to reapeat this step with a variable function?

(where the function takes the coordinates of the last one and uses them)

i used to do that in actionscript by adding childs a function that made a branch.