thanks so much for the information Diver, thats a big help. though i was wondering, do you happen to know how proffesional light controllers (those you buy in a store) are powered? i was also tinkering around with the idea of using a small battery and low power design methods (putting the microcontroller in sleep mode, interupts rather than polling, etc). i think it's feasible, since the lights will be off for most of the day, so the battery should last quite a while. the batteries could be mounted in the unit (kind of like the compartment in a tv remote) an the side of the light controller, and have an led to indicate when it needs to be changed.
thanks again