The Sharp EL-6050 Electronic Organizer, 1995, credit card size organizer easily fitted neatly into your pockets, which probably explains it's demise. It was too easy to sit on it or misplace it.
It's small size (108mm x 68mm x 7.6mm) ease of use and light weight (50g) coupled with calculating power, name and phone number storage appealed to non computer/pda owners.
The electronic organizer was powered by
one CR2016;1 Lithium battery which could run for approximately 2000 hours but was set to auto power off after 7 minutes of inactivity.
Memory capacity in the Sharp EL-6050 was only 863 bytes which was sufficient for a two line 12 digit display. In telephone mode the name field allowed a maximum of 36 characters and up to 60 digits to be input a whole 5 lines (12 digits per line) of information which at the time was impressive.
The Raspberry Pi which is also credit card size is the latest (2011/2012) in micro computing.
Old Organizers Collection EL-6050
Old Organizer Collection Tele-Art PD-100