CTCStore offers Amazon Prime members the Acase Superleggera Case for Apple iPhone 4 and 4S in Black for $12.90. Coupon code "LB5Y4XT5" cuts it to $5.95. With free shipping, that's tied with our April mention and $14 less than buying it direct from Acase. (Non-members can spend $25 or more to qualify for free shipping; otherwise, shipping costs $5.05.) This polycarbonate and silicone case protects against dust and scratches. Coupon expires June 4.

Amazon Prime membership is $79 per year; however, Prime is free for college students for six months, and free for parents and caregivers for three months.