This deal has ended.
Through 8/9 OnSale.com offers a $20 Voucher to PetCareRx.com for $1.99! Since PetCareRx offers some of the most competitive prices for pet pharmaceuticals (like Frontline and Heartgard) this is a huge savings. There is a limit of 1 per person and the value doesn't expire until 2/5/12. Sales tax is charged in most states.