Seems the weakest link in the 30 pin USB cable for iPhone, iPad, iPod, etc is the lack of a stress relief. I like the fixes others have made, and offer a one-piece simple solution.

Prints as a single piece with no support or raft needed.

Printed at default "standard" settings in MakerWare except for fill: 0.2mm thickness, 2 shell, 20% fill.

As printed takes ~12min and weighs ~1.5g.

Slip the cable through the slit, then slide down over connector.
WARNING: Best not to pull the cable to seat the connector! You may break the wire you wish to protect with this thingy!