Just remember when adding an electric motor to anything that will be submerged is going to make it complicated.

Having worked on the Segway develpoment, I can tell you there are no cheap alternatives to a Segway, yet. The components that make it work are still very expensive.

The aircraft tug (if it is one of those small ones designed to fit on the front wheel of a small plane) will definitely not work on sand. They are designed ot work on fairly level paved surfaces. Plus you would have to seal everytign to keep the sand from tearing up the bearings.

After reading all of these posts, it seems the simplest solution would be to mount an ATV winch to a post. Then take the post to the top of the hill, bury the other end of it an inch or two in the ground with it angled "uphill" and have guy wires, two of them, like you would when putting up a cheap dining shelter you can get a Wal-Mart. Use a 12V battery to power the winch and a remote switch to operate it.

This is a totally portable system, the mechanism is kept out of the water, and there are no powered "vehicles" on the beach.

With a little bit of experimentation this could be worked out.