This emergency multi-tool has made its way into my camping pack. For less than $3 delivered, what looks like a Spork has been modified to act as a wrench, for several metric nut sizes, screwdriver, and bottle opener. You can, and I have, also use the screwdriver for prying stuff, and the larger central finger hole can accept a rod for leverage.
The nut sizes are 10mm, 8mm and 6mm. For fans of BMW Airheads, this comes in handy!
Colombia River's Eat N Tool via Amazon