I swear by the Sterling sharpener. Pricier, but it's served me for years and years. ED - Some additional information. The Sterling sharpener features a pair of tungsten carbide sharpening "teeth" set ...

One small inexpensive item I try to keep with me is a packet-sized knife sharpener. If you suddenly find yourself in need, you can put a nice edge on a dull blade in a minute with a small sharpener ...