Wasabi is a Japanese horseradish condiment with head-clearing heat -- be careful not to use it in heavy doses.
Wasabi has a very distinctive, pale lime-green color and is available in two forms: a paste in a tube or a fine powder in a small tin or bottle. When it is stirred into soy sauce, its flavor is toned down a bit, offering a zingy flavor accent. The wasabi and soy sauce combination is also a classic accompaniment to sushi. Some other interesting Asian products include:
Rice vinegar: A vinegar with subtle tang and slightly sweet flavor. There are Chinese and Japanese versions. Seasoned rice vinegar is a sweeter version often used for sushi rice.
Tamari: A slightly thicker, mellower cousin to soy sauce.
Hoisin sauce: A sweet, tongue-tingling blend of fermented soybeans, molasses, vinegar, mustard, sesame seeds, garlic, and chiles.