State Machines

Okay, how many of you guys have heard of state machines?

State machines are functions that perform a small amount of a task each time they are called and keep track of their position in the process using a state variable. State machines are used for multi-tasking; a main loop can call several state machines each time through so each function gets time to perform its duties.

Maybe I can even find time to come up with an example and an excercise if people are interested
--WetWired