A flexible modular system for constructing a wireless communication terminal includes a keypad module and a display module. The keypad module includes a keypad module housing and a keypad mounted on the keypad module housing. The display module includes a display module housing and a display device mounted on the display module housing. The flexible modular system further includes a connector subsystem to selectively alternatively mechanically join the keypad module and the display module to form an integral wireless communication terminal having a first form factor and, alternatively, an integral wireless communication terminal having a second form factor different from the first form factor.