I rarely carried around my compact sized Franklin Covey planner because it was just too big and heavy. I'm thinking the my lightest, most portable set up would be a Palm Treo with a voice recorder (idea capturing device). Or I could go with a real small Moleskine notebook (with small ink pen) with a digital voice recorder with a super small flip cell phone. I'm leaning towards the Palm Treo. Just a bit bigger than my old flip phone, plus I have internet, voice recorder, telephone/address list, and access to all my lists. I could do a PocketMod for ultralight excursions away from the phone or Moleskine.
What is your idea of the ultralight GTD set up with voice recorder and cellphone?