They have one at Kmart. Though I think its supposed to be for one person to pull the string and one to be the shooter, but a longer string, with a loop to go over your ankle works just fine!
I use the one at Kmart by myself. Like I said, I just have a loop in the release string that I slip my foot through. Move my rear foot back a bit, and the target releases.
Made by Trius, called the one-step. Works great, foot activated, fully adjustable, throws doubles no problem. Definitely one of the best things I ever bought! Got mine through Midway USA for about $100.
* there is ZERO spring tension on it when you reset it, once you put your foot on the pedel and step down, it tensions the spring and releases at the bottom of the stroke.
However, if you're not mechanically inclined, you may want to hire me as a consultant to put it together. It took me five hours and several smashed knuckles.
The directions were written by a blind, dyslexic North Korean.
No offense to any of those in the audience