EverydaySource via eBay offers a Bluetooth Wireless Sliding Keyboard Case for iPhone 4 / 4S bundled with a Rubber Bumper Case for iPhone 4 / 4S and an Aluminum Button Bumper Case for iPhone 4 / 4S for $20.99 with free shipping. That's $3 under the lowest total price we could find for similar items sold separately. The keyboard features power-saving sleep mode, a charge time of 2.5 hours, and a standby time of 45 days.