Grab a rock and "love it long time". I think flatter, river rocks are better.
Just buy a sharpener! http://www.dealextreme.com/details.dx/sku.22538
Just use the nail filer that you would find on a set of toenail clippers but be careful not to let the grate stop the blade of the knife abruptly. To avoid this you must be car fuel to use the proper angle
kinda late i know but I don't own a sharpener and my knives are pretty darn sharp. I use anything from glass to marble to leather and even the back of another knife. If it's nice and flat and slightly coarse it could prolly sharpen a blade. it just takes imagination
use sandstone or quartz, a piece bigger than the blade of the knife, and wet it. move the blade over the rock, sharp part first. if you move it backwards, burrs will form on the blade, making it more like a saw than a knife, which is bad.
A simple method for putting a fair edge on a knife is using a pair of scissors opened at a roughly 30-45 degree angle. Run it through like you would using the commercial ceramic ones, and then finish the honing with a leather belt or a pair oj jeans, anything that works like a strop.
call a professional knife sharpener (hmm.. do they still exist? Grocery stores used to employ them only a decade ago) Use a piece of flat sandstone to start, then work thru ever smoother flat stones. erm, but those are sharpeners, so I'm paradoxically constrained. Ack!
Ceramic insulators, and leather belts are good for a finishing stone, but for heavier grit; use sandstone, sand paper (belt sander is best), or cement but only if its smooth and flat. If you don't have a bench grinder or stone, you can use a file, or an angle grinder.
You can hone a very fine edge using the bare ceramic ring on the bottom of most coffee mugs (ceramic beakers) or cereal bowls. It is the different colored ring on the bottom where the cup sat in the kiln and no glaze baked on.
A nice flat piece of FINE sandstone or slate works very well: until recently the best sharpening stones were always natural rocks. An Arkansas stone was a prized thing. These days, the Japanese waterstones are better for a very fine edge, but they are not terribly portable