Allows you to spin crank and rear wheel!
All you need is a hammer, 2 nails and a wood post. Use real manly sized nails; brads and finishing nails won't cut it.!
I have a post holding up my patio roof. I've used this method on a wooden bench in my basement before. You could probably use a tree too.
Don't use a 'nice' post. Your wife, roommate, landlord etc. will get mad at you!
Angle the nails up so a 'V' is formed by the nail and the post. The rear chainstays go in the 'V'.
It may help to lay your bike on the post first to see where the nails would go.
You may want to pull the nails out and re position them.
Rubber tubing or duct tape on the nails will help prevent scratching the paint on your bike.
Granted, your not gonna be sitting on the bike in this rack, but that's not what its for.
The rear wheel and crank can spin for derailleur adjustment, lubing etc. the bike is upright so the brakes, handlebar etc. are easy to access.
Be careful not to put the nails in a traffic area. They are at the perfect knee and shinbone attack height.