Controlling X10 lighting can be done strictly via IR ergo the iPronto can do it. There is a widely available device that accepts IR and puts out X10. There is a version with one house code only so it just receives the unit code/command code (IR543), and there is one that takes in house and unit codes and can execute all possible X10 commands (IR543AH). They are both small and discussed in this forum on any X10 formum. Search for X10. The IR files are located in the files section for both type of units. Go to files for the pronto and search on X10 . No need for RF.