This deal has ended.
This AT&T/ Verizon Apple iPhone 4/4S Rubberized Back Cover w/ ID Slot drops from $7.99 to $3.99 via code CALLERID12 at AccessoryGeeks.com. Plus, it ships for free, making this the best deal we could find by $8. It features an ID slot for storing your ID or a credit card. There is no sales tax (except CA).