Copy from outside mini-SD card to internal micro-SD card

[NebularNovice]

I'm taking a trip where I'll be taking pix with my digital cam, but not taking a computer.  I'd like to back up my pix from the mini-SD cards in the camera to someplace else.  I've investigated several alternatives for direct USB to USB copying with little success.  Then it occurred to me that I have 25+ GB of space on the micro-SD card in my Charge.

Sooo, is there any way to plug an adapter or whatever containing the mini-SD card to the micro-USB port on my Charge so that I can copy the picture files?

It would be a real help, but I'm pessimistic that the technology is quite there yet.

Thanks.