Just to update this thread, Sitrelief shorts are offering a $20 rebate to anyone who gets a prescription from their doctor for these shorts. Even after you've bought them.
Details here:
http://sitrelief.com/index.php/rebate
$20 REBATE
Submit a prescription for SitRelief Shorts from your doctor and receive a $20 Rebate on your purchase. Click here for details
Rebate