Actually, the new minidisc HD is pretty sweet too. There are units under $300 now and the discs are under $10, holding 1GB of data per disc.
You could bring in your HD MD, plug it into the USB port and play your songs for the night directly from the player. Pull the data disc out and listen to music on your way home.
You could even offer a conversion process to your customers. They purchase the disc and you convert the tracks and put them on minidisc for them. They just bring in the data minidisc later.
Please note that the standard minidiscs will also hold data in the new HD players. Something to the tune of about 330 MB's or so and are available for about $1 each in quantity. Also note that the standard players you find for about $100-150 do NOT handle data. There was a minidisc data player a number of years ago but the formats are incompatible.
I'm adding a minidisc player ot my setup for playback and recording of my shows for marketing. I can have a potential customer listen to a show to hear me in action. I can also use it to better my skills at doing a show. BTW, as long as I don't distribute or play it as on hold music I should be ok with this legally.
Ok, so perhaps the minidisc isn't as small as the USB devices, but I think the versatility could make up for it. Add in the low cost of the discs themselves and it might be a winner.