Are there any modules I can control that does not have to be plugged into an outlet?
No. All X10 controlling modules require line voltage. You can use a X10 Universal Module (or the Smarthome equivalent) to close the contacts on a Roomba remote control which are available for 400 and 500 series. Not sure if iRobot has a remote for the new 700 series.
There are 12V RF relays operated by a key fob, for custom use in automobiles. Ebay is a source, but since the Roomba's battery is 15 or 16 volts, you would need to make a 12V power supply to power the radio controlled relay on the Roomba. A 12V regulator like a 7812 would do it, but there will be a lot of hacking to be done on the Roomba.