Nokia recently filed a patent design that features a cell phone with a removable built-in joystick for cell phone gamers (read patent).The invention claimed is:
"1. A handheld device comprising: a main body having processor components operatively connected together for performing predetermined functions; a stylus; a ball defining an orifice configured for receiving said stylus; and a socket defined by said main body for rotatably receiving said ball, socket being configured for generating to said main body electrical signals indicative of movement of said ball in response to movement of said stylus, said processor components including pointing device logic for responding to said signals."

No word yet from Nokia when this phone may be available.