A4C offers the Chromo Waterproof Case for iPad in Black for $8.95 with free shipping. That's tied with our December mention and $6 under the lowest total price we could find for a similar item elsewhere. It features a neck strap and is compatible with 1st-, 2nd-, and 3rd-generation iPads and the iPad mini.

Update: Note that coupon code "SPRING10" cuts the price further to $8.06.