Even the challenged, maybe even a member of congress, can sharpen a knife with Accusharp.

Here is a page of Accusharp products
http://accusharp.com/products/index.html

After a few years even Accusharp blades dull.
Store new tungsten carbide blades inside the handle of each sharpener.
http://accusharp.com/products/003/index.html

I have a 001 sharpener in the kitchen, one
on a dummy cord attached inside the packsack that
lives in my 4x4, and have given several to those I care about.
http://accusharp.com/products/001/index.html

The AccuSharp Dual Blade Turboslide Knife.
This tool combines the functionality of a sport
folding knife with the usefulness of a utility knife.
And this utility knife is designed with a quick change
mechanism to simplify changing the razor blade.
It also comes with five replacement blades for your
convenience. Constructed of anodized aluminum and
stainless steel, this tool is built for years of rust free
use and comes with a lifetime warranty. A carabiner
clip is also enclosed on the knife to keep it close by and handy.
http://accusharp.com/products/706/index.html