Used to use one of those things that stuck in the ground too but hated them.
Up until last year, I used a product called BowLegs. They are pretty cheap, and can sometimes be found used for even cheaper. The problem with them is that they weren't very stable if the ground wasn't hard or nice and smooth.
http://www.polemountainoutdoors.com/index.php?page=mods/Products/itemdetail&itemid=10Last year, I invested in a set of BowStix. They are a little spendy ($60), but absolutely awesome! The legs screw together and then fit right into your quiver. Get to your blind, take the legs out of your quiver, and screw them into the thing. Your bow is upright and stable as can be..
http://bowstix.com/Ive also seen a clamp-on thing that goes on your bottom limb that seem to work ok, but the problem is that you have to take it off before you shoot, so it involves one more step.
http://www.basspro.com/Vista-VPod-Kickstand-Bow-Stand/product/1108311690057/