Looking For a Good Gallery Script

Hey everyone,
Im looking for a gallery script with effects like lightbox, the only thing is that I want to be able to have multiple galleries on one page. Each would be selected by a thumbnail and then be able to navigate through all the images in a selected folder.

Each gallery would have its own folder.

Does anybody know if there is a free open source script out there that will do this? Or does anybody know how hard it would be to modify lightbox or milkbox to meet these needs?

I really appreciate it.

EDIT: Im wondering if lightbox 2 does this already.. i didnt know they made a new version..