Check this out.
Davron Marine Products (Dinghy-Tow)
It's actually really nice when you see it in person. I have seen two and liked the set up. Yes; it has drag, but works nice. It also folds up against your backstay. I talked with a transient extensively and he and his wife loved it.
For short hops i think it would be great. For long trips i would put my dinghy on deck.