For $40 you can buy a Harbor Freight belt sander. The belts are 1" wide and 30" long. It's a workbench model and you hold the knife edge up to the belt while is running. There are many videos online about how to use them to sharpen. I also own several other systems, including the Lansky, KME (better made Lansky), Japanese water stones, and diamond stones, but once you get used to the belt sander, you forget about the others. You will need to buy some fine grain belts online.
Purists will tell you it is heresy to use a belt sander for this purpose. I have so many different implements that need sharpening, however, and this is the fastest easiest way I have ever used. (Try sharpening a long machete on one of those other systems.) When friends come for dinner now, they bring all of their kitchen and other knives that need sharpening. Fifteen minutes later, everything is sharp sharp sharp. You touch the blade lightly to the belt until you feel the burr come up on the other side, then rotate. Then switch to a finer grain belt, or even finish with a leather belt and rouge. Just don't let the blades get too hot or it could ruin the strength of the steel.
Sander:
http://www.harborfreight.com/1-inch-x-30-inch-belt-sander-2485.html
Belts:
http://www.theedgemasters.com/SharpeningSuppliesforSale.html?gclid=CL-T_avGhrQCFYuZ4AodOHgASw
The belts are $8 each. I think I have a 120 grit, 400, 800, and leather. I also have a very rough 40 that is used to put new edges on an axe or machete.
Youtube video. Dull knife to shaving hair in under 5 minutes with the Harbor Freight.
http://www.youtube.com/watch?v=DTQttzLrdtU
Of course, you can't carry a belt sander in the field with you, so you do need to maintain some hand skills to use when you're not at home.