What is the magic so that I might select some flash memory device for
use as a boot device?

I suspect that there are device features that are favorable to this task and other features that are not-favorable. I'm not trying to use any of the excessively win-dose-centric "security" or similar devices.

I've tried to put linux (Ubuntu CreateBootUSB, DamnSmall, CloneZilla, SystemRescueCD, etc) onto any of several "geek stick" "thumb drive" "key drive" USB devices as well as various media cards without success.
My systems will boot from USB, but I cannot get the right bits onto the devices --or-- I have the right bits but the device won't boot.

~~~ 0;-Dan

"Geek Stick"? I have never heard that term before...

As for booting to USB devices or flash cards, no special support is required on the devices themselves, as long as the motherboard supports USB boot, it should work. It sounds like some part of your setup isn't right, but you didn't really give any details on that.

Here are two sites that might help you in your quest. Good luck!

http://www.pendrivelinux.com/
http://unetbootin.sourceforge.net/

My troubles have been various and cut across several items of target media. I was using the same dance with different media and suspected that I was using the wrong parts as a target.

Now that I know ... because I learned it here (grin) ... that any "thumb drive" or "key drive" or "USB drive" or "flash drive" is supposed to work so long as BOOT_USB or similar has BIOS support, I'll watch my process for errors and return with details.

~~~ 0;-Dan