Lightest knife +

The Trango Piranha is pretty light/simple/compact

I found the Spydeco site useful. They list many knives.

The lightest I found were the Finch, Dragonfly, and Ladybug. All weight 0.6 oz with blades just under 2 inches. I'm considering one of them to replace my small scissors in my first aid kit.

Happy hunting

LV

Take this for a knife

found Here on BPL, and 2 quarters for the canister.

The lightest of the lightest is a single-edge razor blade from the hardware store. This is a nice tool and (with a homemade holder created from a piece of cardboard) it weighs a remarkable 0.1 ounce (see the illustration above)! I feel like the holder is required because I don’t wanna reach in my pack knowing there’s a really sharp thing in there.

Here's a LINK to a BPL article:

http://www.backpackinglight.com/cgi-bin/backpackinglight/ultralight_knives.html

I found that sometimes the bear canister really needs some force to close the screws. Enough force that you will bend the blade of the lighter pocket knives. Hmm… maybe if I didn't try to get 27 meals into a canister which is meant for 18 :). Anyway, I suggest taking a quarter for the canister (dual use if you can find a pay phone) and then find a knife that's good for everything else.

–mark

Scott-
For a knife that would address BOTH your requirements, look at the Victorinox line of swiss army knives. My brother has one with around a 2.5 or 3 inch blade that opens one direction, and a bottle opener/screwdriver that opens the other way. None of the other junk they offer, not even tweezers or toothpick (I think). It has a nice thin form factor. Haven't weighed it but I just used it the other day and it could not be more than 2 oz, less without the red plastic sides.

If using a Bareboxer,you will need a screwdriver like or golf cleat key to open. I take a Leatherman Micra. Small enough I don't notice it. Big enough for me to find it. The Phillips screwdriver blade works great on that canister. And it has good scissors and tweezers as well