PC Micro Store offers select TPU Crystal Skin Cases for iPhone 3G and iPhone 3GS for $6.95. Coupon code "IP3GTPU" cuts them to $2.99. With free shipping, that's tied with our mention from two weeks ago and among the best such offers we've seen on iPhone 3 / 3GS cases from this merchant all year. These cases claim to protect your iPhone from scratches, dust, and more. Coupon expires after 1,000 uses.

A best bet is the Young Micro TPU Crystal Skin Case for iPhone 3GS in Smoke Flower (pictured) for $6.95 before the above coupon, $2.99 after. With free shipping, that's $17 off and tied with our mention from two weeks ago as the lowest total price we could find. This item comes with a screen protector.