But it's worth pointing out that while this will probably power the scanner perfectly, charging the batteries while they are in the scanner doesn't work all that well, they charge very slowing, most likely taking several days to charge to nearly full from nearly empty. This is due to the way the scanner is designed and has little to do with the particular USB charger you choose to use.
Agree with all of the above. Any cell phone charger good for at least 500 mA, which are available usually for cheap just about everywhere, will power the scanner, but get a decent external charger for the batteries. They will charge quicker and last longer, and you don't risk destroying your expensive scanner should a cell decide to start leaking.