My Leatherman

I own a small keyring one: http://www.leatherman.com/24.html I formerly had a Gerber equivalent but the blades weren't sharp and the overall weight was high.

This one opens in a quite different way but is a 'heavy duty' tool and not so functional for pocket use. Good for a bag/tote/backpack though: http://www.leatherman.com/49.html#prefn1=sizecategory&prefv1=Heavy-Duty&start=5