The portable device I am talking about is the T-Mobile G1 Android cellphone. Android is a software stack for mobile devices that includes an Operating System, Middleware and key applications. Presumably, the T-Mobile G1 contains an ARM EABI architecture which is supported by Debian.
So a group of people (hackers) set out to install Debian on their T-Mobile G1 Android phone. The end result, at the least, is quite interesting. They have succeeded in running a full fledged Debian OS on their G1 Android cellphone at the same time, retain all the features which allow it to function as a cellphone such as receiving and making calls.
Read a detailed write-up on the steps needed to install Debian on a TMobile G1 Phone at the following website. AndroidFanatic.com has released a Debian installer script for your Android cellphone which you can download here. Watch video also.