The Portable Telephone is an old plastic push-button telphone upgraded to the cellular age. Within days of finishing it, Tristan Perich read about the Pokia/Hulger and then NES's rotary. But this one dials, rings AND charges.
The process involved ripping apart a cellphone and wiring corresponding parts between his cell phone and the disemboweled landline phone. The vibrating motor that usually warns you of a call on your cell phone is used to excite the old fashioned bell ringer, which is quite loud.
The cell phone charger was spliced and adapted to fit the standard phone jack on the back of the phone, so it doesn't ever need to be opened.