hold as much weight as you can in your hands (helps build forearms and grip at the same time).
step up onto a ledge a few inches tall.. let the back half of your feet hang off the edge, and then let your weight push you down, stretching your calves (but dont let your heels hit the ground). then stand up on your toes as high as you can, clenching your calves.. repeat, up and down, but slowly, don't "bounce". feeeeeel the burn (and you will) :Q