Ok, I'll bite - here are some scenarios where my knife(s) would come in handy in an urban/shelter environment. For reference I work in an urban / office environment and tend to carry a wenger esquire moneyclip knife (small blade, small scissors, nail file) a small locking folder (think benchmite size) for slightly more serious work and a small multi-tool (squirt E4).

Here are the sorts of things that just the moneyclip knife can be used for:

Opening boxes / packages - it seems everything is buried in plastic or cardboard with strapping tape these days. I think this would include some prepackaged supplies the shelter might have around.

nail file is tolerable as a mini, very light weight prybar (for opening stuck battery doors on radios, toys etc.)

nail file is tolerable makeshift screwdriver (standard and phillips)

cutting tape - I can't ever get the stuff to tear evenly.

whittling plastic things down to a size that I can run them though various size holes (think running electrical cords)

opening watch to replace battery (careful, this is a great way to cut yourself).

stripping wires - takes some practice to avoid nicking the copper.

Getting CDs/DVDs out of those annoying slot loading drives.

punching a bigger vent hole in my coffee cup

prybar for lifting Coca-Cola can tabs

Getting coins unstuck in the feed slot for vending machines.

Cutting those annoying zip ties that are everywhere these days

Cutting fabric into strips - lots of possibilities from bandages to restraints to lashing.

Jimmying the wimpy locks on most cheap office desks/modular furniture (takes some practice and doesn't always work) to find more supplies/options. I am not advocating theft/looting but I have broken into my own desk a couple of times.

changing jumpers on computer equipment (scissors & nail file).

That extra 2" stretch for the thing that just fell behind the partition and is almost in reach.

Shorting out low voltage lines - think doorbells, various control circuits - please be sure it is low voltage before proceeding.

I am sure others will think of several things I missed.

- Eric

Accept the challenges so that you can feel the exhilaration of victory. 
- General George Patton Jr