Other portables

• Nestable
  A collection of links and information about NES portables (including a design for a somewhat chunky NES portable)
• Portables of Doom
  A clearing house of information about building all sorts of portables. Currently AWOL.
• Ben Heckendorn's site
  A pioneer in building portablized games, includes an instructional book on portable building (available for purchase now!), a forum, and lots of info.