After my leg workout is finished I like to blast my calves in this manner; I'm pretty sure it isn't new, but I haven't seen it anywhere else and I devised it myself so thought I would share it and see what people thought:
It's done on a standing calf raise machine, and it involves a mixture of high rep sets moving down to lower reps with static contractions. Rest 45 seconds between sets, reps should be slow, controlled and full-range. Your calves should also be fully warm and worked by this stage.
Set 1 - 30 reps
Set 2 - add 50% to the weight, do 20 reps and then hold on tiptoes for 10 seconds
Set 3 - add 50% to the weight, do 10 reps and then hold for 20 seconds
Set 4 - add 50% to the weight and hold on tiptoes for 30 seconds
Set 5 - Take your starting weight, perform 12 reps and hold for as long as you possibly can!
I've seen some good progress in both size and strength using this method for a couple of months, hopefully it might be of use to someone else. Apologies if I'm stealing someone else's idea!