Could easily be made with hollow box uprights, run the water tube through one and the top hollow box with a PVC tube that you drill holes in for the water to run out. Faux paint it to look like copper, really pretty easy.
Recycled Wood Planter Box. This comes with a pdf showing you how to construct this planter. It's very easy and you only need basic knowledge to construct it. Although not made from old pallets it is made from recycled wood.