The ucLinux folks have a SIMM with a Motorola 16mhz DragonBall processor, 2meg flash ram and 8 meg of dram.  Runs ucLinux and, with a bit of hacking I guess, would run Squeak.  Doesn't have a display though they claim it will run a 320x240 mono LCD panel.  It'll be a touch bit poky and you probably don't want to run morphic yet :-)

Along those lines they also have a port to the Palm Pilot.  The catch is you have to use and add-in board which seems to be discontinued.  

cheers

bruce