We are still running a special on possibly the easiest PDA to ever exist, the DataRover. It uses the MagicCap OS and uses a real-world metaphor for interaction.
Pictures of the unit are located here.
After looking at the pictures I am sure you will agree that the DataRover takes the desktop metaphor to the logical conclusion. :-)
Link to the special offer page.
Brand New units for sale for the low price of just $15!