the big question is how much do you want to spend (and are you turning off the fixtures or just the bulbs)

the best way is for IR is generally via a Lutron GrafikEye or a Radio Ra2 system (Dimmers, IR keypad and preferably a main repeater)...both solutions are going to start at about $1000 though which I'm guessing is out of the budget. It also helps to know what remote and rf base station (or processor) you're using.

There are also a few stand alone devices that will allow you to send it a code and then run its own delay or a full macro as well...or you need to upgrade to a higher level control system that has a processor rather then just an RF to IR repeater.