Charging up a battery - USB or A/C

[AmberClad]

I have an MP3 player and a GPS unit. Both can be charged up with either a regular wall plug, or through USB. Is one preferable to the other?

 

[JackMDS]

If you have a functional choice I would go with wall.

 

[bruceb]

Wall charger is the better way. On board usb ports are limited in the current
they can supply and using them near their maximum can cause them to
fail early.