For day to day sharpening/touch-up I just do a few strokes on ceramic sticks. I am awaiting a Lansky (model 21) two-stage Crock Stick with wood base that I ordered earlier this week. A pair of fine ceramic rods have worked OK, but the course thinning rods should make sharpening even faster.

I have tried unmounted oil-stones, they're OK, but the Lansky system is better. If you're really serious, a belt sander system is worth investing in. However, if you don't use a knife too heavily and usually touch it up before it's very dull, a simple pair of crock sticks in a base that holds them at a fixed angle is super easy to use. I've heard nothing but good about Spyderco's Sharpmaker; its only drawback is that it's more expensive than most other sharpening sticks.