They're one of the standard measures I use. If you have an a/p with two antennae, substituting one with a directional antenna may work wonders. It does not matter whether you install it on the access point or on the client -- sometimes you're precluded by the fact that your antenna connectors do not match, or the antenna be separable at all.
Last edited by DBTL; 25th April 2006 at 16:48.