What you are asking about is definitely "doable" with the right type of switches. PCS switches can be programmed with different "ramp rates" from instant up to 13 minutes. Each switch can remember up to 16 different "ramp rates" and 16 different dim levels. For example, you could program 10 PCS switches in your home to turn on with one X-10 command. They could ramp up at the same rates or at different rates, and they could go to precisely the brightness level you want. The only hardware needed for this is an X-10 transmitter, PCS switches, and possibly some help in programming the switches for these lighting scenes. By the way, Leviton switches do not allow the ramp rates to be changed (default is 2-3 seconds).
We are an authorized PCS product dealer and can help you select the right switch and provide you with the technical support to get the results you want. We have helped other Remote Central people set up lighting scenes with PCS switches.
RCI Automationrciautomation@compuserve.com[Link: ourworld.compuserve.com]