A remix of pbeyl's "Yet Another Micro SD Card Storage Case" which was itself a remix of bgill's "Micro SD Card Holder" to turn the center four MicroSD card slots on both sides into nano USB device holder slots... because I don't have 16 MicroSD cards I carry around, but I do have several MicroSD cards plus some nano wifi, bluetooth, etc USB adapters that I normally just keep loose in an Altoids tin.

Modifications to the bottom were simply cutting out the solid material between two of the existing MicroSD slots, then extending the now thicker slots by 0.5mm toward both the center line and outer edge to make them slightly wider as well.

The top was extended by 5mm to give a bit more headroom for USB devices of varying heights, as my Edimax wifi adapter is only about 2.5mm taller than a MicroSD card, but a Fitbit USB adapter is as much as 6.2mm taller. That said, even with the extra height inside allowing the MicroSD cards more slack space to slide up and down when it's closed, it still seems low enough to keep them from actually coming out of their slots even when shaken with intent to dislodge them.

Note: The top does screw on pretty snugly, and I followed pbeyl's comment on his model to soften it up a bit in some hot water, and worked it back and forth until it was a bit easier to screw on and off.