Water in the amount sufficient for an all day hike is not really "tiny" or featherweight (1/2 gal minimum). So the backpack must be comfortable and the person must know how to wear it comfortably. Camelback type with the waist strap and chest strap engaged is the way to go. Almost unnoticeable, especially if you allow enough space between it and your back on a hot day. So, I would start from explaining obvious benefits of hydration, point to the most unobtrusive way to carry the required amount, and eventually make a suggestion on other survival gear which will fit there easily "just in case".

Good points - make it easy. ( and include sunscreen & bug dope)

For a tiny pack, REI Outlet currently has a Pacsafe Venturesafe 150 Cross Body Pack - 2012 Closeout on sale for $27.73.

http://www.rei.com/product/856329/pacsafe-venturesafe-150-cross-body-pack-2012-closeout

I got one to try changing my EDC "system" from a waist pack, mainly because it is large enough to carry a 7-inch or 8-inch tablet computer. It holds an iPad Mini with protective case just fine, with a small amount of remaining room for extra gear. I'm pleased with its quality/construction.

Steve

Instead of sunglasses---

Tibetans use strands of yak wool. Sort of like polarization.

Do you think that pack would hold a pair of medium sized binocs?

A definite maybe!

This video is the best I've seen for showing how much you can cram into it; there are others, too:

http://m.youtube.com/watch?v=IUS1WepdSDk

For medium binocs it would be hard to say. If it is any help, prior to settling on the iPad Mini I was able to just fit a slightly smaller 7-in. Android tablet into the pack, along with a plastic VHS cassette case that was crammed with supplies, plus a sleek 3-cell AAA flashlight and a small amount of other supplies. I had to ditch much of that to hold the larger (mainly wider) iPad Mini.

HTH,
Steve

There is a larger Pacsafe if you like that format but need it bigger. Pacsafe Venturesafe 325

Frankly ???
I have long since gave up on people
They can live their life (and die) their way
All I want from them is to let me live my way

Not only they won't listen or do the right thing, they will think and say all kind of noensense about you. And when they face emergencies, they run to you for help. Grrrrr.

PacSafe crossbody looks interesting. I'll check it out.
I really wish that people who did YouTube's were more action-oriented. It would have helped if she had demonstrated a couple of different ways of putting on the pack ... more useful than knowing what compartments exist.

Pete

The Grand Canyon National Park does a pretty good job of this -- their signs warn of the dangers and there was a sign telling the story of (if I remember correctly) a marathoner who died hiking down from the rim. But maybe I feel that way because I read the signs. Many don't.