Airplane Restraint/Hold-Down
Made mine out of 3/4" copper pipe with two elbows and two end caps to form a "U". The used a length of threaded rod (with washers and nuts) through the horizontal part of the "U" to make the part that goes into the ground. Wrap with foam or pipe insulation and you're set.... cheap and easy...
The PVC would work too... I had the copper lying around