No doubt a 30-pin USB sync & charging cable is a must-have accessory for your iPhone 4, but if you always forget carrying the USB cable, Cord-On-Board iPhone 4S case should be suitable for you.
Cord-On-Board is an one-piece protective case designed for both iPhone 4 and iPhone 4S. The iPhone 4 case features a bit tough design, and is made of shock-resistant thermoplastic material in order to protect the iPhone 4 or 4S from shocks and scratches, while the curved backing provides you a comfortable grip experience, or makes your iPhone 4 stand in landscape or portrait viewing mode. More importantly, inside the protective case, there is a well-designed room for an accompanying sync & charging cable, so you can conveniently sync or charge your iPhone with the integrated USB cable. Apart from that, all the iPhone 4 buttons and functions are accessible via custom cutouts.
At present, the designers of Cord-On-Board iPhone 4/4S case are raising fund on Kickstarter. Pledge $25 will let you own the iPhone 4 case. If you’re interested, jump to Kickstarter for more details. Additionally, also don’t miss other nice options via “iPhone 4 case” tag.