How many different things can be called ANT? There is a build tool, the insect, a typesetting system, and a wireless protocol.
I was completely unaware of the wireless protocol until recently. ANT is a 2.4 GHz short range system used primarily for telemetry. For example, the Polar heart rate monitors use ANT to get data from the associated chest strap.
They talk about data rates from 1200 to 57,600 baud. Power consumption in micro and milli amp ranges. Each device is addressable and there are broadcasting capabilities.
One merchant (Spectec) has created a miniSD card that has an ANT RF receiver built in. This allows a phone or PDA to receive data from sports sensors.
If you visit their web site (http://www.thisisant.com/) you’ll find complete specs, ready-to-use products and development kits.