USB portable external speaker

I'm moving to the MBA from a Sony Vaio for a traveling laptop for giving presentations. I'd been using a Sony portable USB speaker with the Vaio--just plug it into a USB slot and the presentation audio comes through the portable speaker instead of the internal. I can't seem to get that to work on the MBA, even when I set the sound effects to play on USB codecs instead of internal speakers. Can the MBA drive an external USP speaker?