Every once in a while you can find something cool in those little ads they run in the back of motocross magazines.
I found this item in the back of the latest Racer X Illustrated: it's a ride-on bikestand being sold by a company called Risk Racing. They even have a little flash animation demonstrating how it works. And it looks like it works pretty well.
Just the thing for tired old vets after a long, 4 lap moto!
They also sell a practice starting gate, but this one has a twist: it has an electronic delay starting mechanism, so you can practice starts without a helper. Again, check out the site; it's pretty cool.