True, my knife can't do those things, but my backup can.

http://www.leatherman.com/products/tools/s4/default.asp

In total, the two knives I carry are both tiny and add up to a mere 4 or so ounces. I know a lot of people never use nor ever find a reason to use a knife while backpacking, but I carry two because I often have a need of both of them (but not together...).
_________________________
Hike Arkansas! and Hike it All!