Eddie Bravo of 10th Planet Jiu Jitsu demonstrates a nasty calf crush/toe hold from an unnorthodox position found in his system called 'Stoner Control.' As with all leg submissions you want to be very careful when sparring with your training partners.
In the video below Eddie shows two variations. One is from Stoner Control, the second variation is a rolling lock from Stoner Control if you are not able to get the submission from the first position.
The second variation is pretty cool because after you complete the Stoner Roll, the submission is right there and as Eddie explains in the video, your opponent is completely defensless.
