Cosmos ® Black Cable 3 Ft USB Charge and Sync Data Cable + Dock Connector Extender Extension Cable for Ipod Touch Iphone 4 4s 3 3Gs + Cosmos Cable Tie
Works great for what I needed it for (connecting to MOPAR iPod cable), but it looked like it was used.  The cable ends were all scratched up and dirty.  But it was cheap and works.  I haven't used the 30 pin to USB cable yet, I just needed the extension cable and this was the cheapest highest rated option.