yes. The design is layers of blocks as follows (I can't send pics, as I am on the work computer):
ring of 10 blocks with a 1x2 hole in the middle. water flows to the bottom inside those 2 blocks, and hoppers collect the drops at the bottom. the 2 center blocks at the ends of the ring hold up the next layer, and also force the pumpkin plants to grow fruit in the middle blocks (yes, dirt)
The four corners have one plant each, and the pumpkins grow on both sides next to the water. there are pistons behind those to push the pumpkins off.
If I remember correctly, it looks likes this:
X=any block / P = piston / T = tilled earth / D = dirt/ S=space / W = water / L = ladder