Motorola Mini-USB to Micro-USB Charger Adapter - $2.55 on Amazon

I guess this isn't really a phone accessory but more of a charger and cable accessory.

If you are like my wife and I and upgraded from an older phone you probably have accumulated several of the Mini-USB chargers and cables. For instance, we have been using a nice combination car and wall charger that is perfect for travel, but it didn't work with our new phones because it is Mini-USB rather than Micro-USB, apparently the new standard.

This cheap adapter allows us to use all of our older chargers and cables. It works for both power and data connections.

PS - famous quote: "the nice thing about standards is that there are so many of them"