I'm sure it's not per code, but when I moved into my house, there were2 switches installed for the front porch lights (one at the front door, one in the basement by the distribution panel). The one by the door was a standard switch that operated as any other would. The one in the basement was an electronic dusk to dawn type timer. I think the wiring is installed similar to a 3-way, but it wasn't wired that way. If you turned the front door switch on, the lights would come on. If the dusk to dawn timer was activated, the lights would come on. But, if one was on and you wanted the lights off, you could not switch it off from the other location.
This setup is basically what you are suggesting. The thing is, it's probably not legal since there are multiple ways to energize the down switch side of the circuit and without knowledge of the wiring, you could get seriously hurt if you were changing fixtures for instance. Of course, you are supposed to kill the breaker anyway...
I decided to rewire and add X10 (since there was already some installed anyway). I installed a Smarthome X10 toggle switch at the front door and disconnected it from the load. I replaced the one in the basement with a WS13A. In retrospect, I could have just disconnected the one in the basement and just used the Smarthome switch for the same effect.
Either way, this setup can be accomplished, but in my opinion, it's not a very good idea even if it were legal. Also, it may be bad for your X10/Smarthome/etc switches if you did this since there would be power applied to the load side which the switch may not be able to handle.