All4Cellular offers the refurbished LifeProof Case for iPhone 4 / 4S in four colors for $21.99. Coupon code "SUMMER10" cuts it to $19.79. With free shipping, that's the lowest total price we could find for a new unit by $2, although we saw a refurb for $2 less in April. It features 6.6-foot drop shock protection; it's also waterproof to depths of 6.6 feet. Coupon expires August 23.

A 90-day All4Cellular warranty applies.