reading through the thread, i kept thinking it sounded a lot like functions in painter... but like lucie said, you can probably create a similar effect in photoshop.

a lot of times i scan random watercolor pieces and other effects (such as salted watercolor) and use them in pieces that i want to replicate traditional works. 

do you have a sample of something you'd like to achieve?

it'd be fun brainstorming solutions....

:)
retrocity