Friction

Friction is the use of a rough-surfice to buff away hair from the surface of your skin.
You can use anything from a pumice stone to a specifically designed hair removal mit.
Different products are available for different areas of the body, though the most common areas are the legs and arms as the skin is flat and fairly durable. However, specific firction products are available for areas such as the face and bikini area as well.
Lots of people like to use friction as an upkeep method between waxing sessions.

Advantages:

Inexpensive, fast, essentially painless, can be done at home, available widely, also exfoliates and smooths skin. Many types can be used wet or dry. Good for legs with fine hair. Some use it between shaving or waxing sessions.

Disadvantages:

Effect lasts a short time-- anywhere from a few hours to several days. Dark-haired users may have visible "shadow" of dark hair under skin. Often requires use every two or three days. Can cause skin irritation if rubbed too hard. Do not use on face, arms, or bikini area. Do not use on irritated or damaged skin.