Although the steps needed to do batch resize images on Snow Leopard are more or less similar to those batch resize steps for Mac OS X Leopard, there is a simple workaround needed to perform batch open and resize images on Snow Leopard.
While resizing all my images, photos and wallpapers, I came into this great trick to easily batch resize images that I've never read somewhere else before; You can simply use Preview to batch resize images.
Wanna know more?