Thing that keeps the door open

Anybody got a spare bendy bit of metal that stops the door closing when you want it to be open? Trying to work on the car on a sloped drive is driving me mad - you can either have the door closing on your leg or it puts a dent in the Multipla parked beside.
I found half of one inside the driver's door - it's a piece of steel rod bent to a roughly Xmas tree shape.

Check out ebay, there's just been a couple on there! Failing that CASCU or Alternative Autos are your men!

Cheers,

Nige