Somebody's blog I browsed on showed where she made her own rocks to outline or edge her flowerbeds. If I recall correctly, she mixed the concrete(Quickcrete in a heavy plastic bag, and molding it into a rock, when it was molded into the shape she wanted, she put it out for the sun to dry it so it would harden.

I have also seen molds to make your own bricks, cobblestone walks,etc. Has anyboyd tried these molds and where do you buy them from?