Steve,
I think you are mistaken. I have a three-way switch for my hall lamp; I can switch the lamp on or off from the landing, the middle of the hall or by the front door. This circuit uses 'normal' mechanical (i.e. not solid state electronic) switches.
There seems to be some confusion about the defifnition of a three-way switch. I always understood a lamp controlled by two switches as a two-way switch. However, most wiring diagrams on the web seem to show two switches for a 'three-way circuit' and describe a circuit with three switches as a 'four-way' switch! Whatever!
This link shows both, with videos:
http://www.askthebuilder.com/B141_3_Way_Switch_Wiring_Diagram_and_4_Way_Switch_Wiring_Diagram.shtml
As an Engineer, the only schematic I can reason out is the standard 'parallel wires with a switch at each end' diagram with a third, double pole switch in the middle that either 'completes' the two wires in isolation or 'crosses' them. Think about it this way; the two parallel wires A and B have ends A1 and A2 on wire A, and B1 and B2 on wire B. The middle switch would either connect A1 to A2 and B1 to B2 or in the other position, connect A1 to B2 and B1 to A2. It sounds confusing, but is pretty straightforwards really.
Either way, the switch you seem to be describing DOES exist and, speaking from personal experience, is really useful!
All the best,
Phil, November 2008