My HTC Desire Z came with a charger that consists of a mains electric plug with a USB socket for attaching the phone to to charge via USB.
Other devices such as the iPod touch can be charged via USB.
Assuming that there is a standard for USB powered charging, i.e. a amp/watts/voltage rating, then could these devices be charged from the same adapter, safely and effectively.
This would save money buying additional mains adapters, when, for example, the iPod touch does not come with a USB mains charger, though it does come with a USB sync cable for iTunes and also for USB powered charging from a PC.