Kip,
I recently purchased the DR Power Grader. http://www.drpower.com We have a 1000 foot gravel driveway on our property as well as about 1/3 mile shared gravel drive to the road. The road had potholes and washboarding pretty bad. Prior to getting the powergrader, every year the neighbors and I would have gravel put down to "cover" the potholes, etc. (which didn't really work very long before the washboarding came back) and with the cost of gravel going up rapidly, this gets quite expensive. After using the powergrader, which I pulled behind my JD Gator, the gravel drive and road is SMOOTH. Potholes and washboarding are GONE. This unit really works! It costs more than the other options that some of the other folks are suggesting, but this thing is built like a tank, and I expect it to last many years. What's nice is that you can adjust the depth of grading into the gravel drive with the electric actuator while on the move. This gives you ultimate control in moving the gravel around. Definitely check this thing out. I swear by it. Michael