Here's an interesting little gizmo that's appeared in the Apple Store:
This allows you to charge your iPhone using any micro USB charger that outputs 5V at 500mA.
This bring Apple into compliance with new European Union standards for smartphone chargers that the company signed up to in 2009. The standard is meant to reduce on electronic waste and to simplify the live of smartphone owners.
The adapter is currently only available in the UK and costs £8/$12 (pretty pricey for an adapter) and ships October 14. Apple rates the adapter as compatible with iPhone 4S, 4, 3GS and 3G. Not sure why it wouldn't work with iPods and even iPads for just syncing.