From the "Look like a BB..." article:
Again, my point is, if you do a lot of heavy squats, deadlifts, and the right kind of sled work, your calves will receive all the stimulation required to blow up. That being said, if you still insist on working calves, here's how I would do it:
I would work the calves directly only once per week at the very most. I would also use constant-tension techniques and long, time under combined tension.
For example, this means choosing one lifting exercise, like standing calf raises, and superset that with sled backward tiptoe-walking for 20-30 yards per set. As far as the calf raises, I recommend performing 10-12 reps, pausing two seconds at the bottom (to remove the stretch reflex) and holding two seconds at the top (to increase time under tension).
Pretty much what BiP was saying.