These are Personal Data Assistants with a rather nice Operatign System and a slightly different way of thinking.

They are also commonly refered to as Palm Pilot's - the name of the original first model.

While linux says "Everything is a file", and windows makes it up as it goes along, to Palm OS - everything is a database, record or table.

There are program to interface their Infra Red ports with Cybot and the Lego RCX. There are also programs to interface 3-series serial ports with other serial devices. Quite versatile - abd you can store all your phone numbers on them as well...

PPRK - Palm Pilot Robot Kit

Some books worth considering:

The Ultimate Palm Robot Kevin Mukhar, Dave Johnson What can I say. This book is amazing. Take your old Palm(a IIIc perhaps) and turn it into a serious robot base. Including software, electronics examples and other stuff - this is a wonderful book. I am only sore that I didnt find it before.