I have this problem. I was experimenting if I could use a memory card (SDHC) as an USB drive for all intents and purposes, and when I put the card in an USB card reader, I can use it just like a regular USB stick, and it also shows up in the BBS popup menu as an USB stick. When I tried to create an installation media out of it like this:
sudo dd if=/path/to/image of=/dev/sdb
And tried to boot from it, simply nothing happened. Cursor blinked a couple of times, and jumped to the GRUB of my pre-existing GNU/Linux installation. What am I missing here? Is this not doable?