[Pontiac]

It should be a write rarely, read often type device. System RAM is used for repeated re-writing tasks.

Seems like having a Computers OS located on Flash memory would be an ideal application.

The OS is rarely over written and having it on Flash would mean quicker boot up.

[pgobrien]

http://portableapps.com/
There are some tricks to getting a OS on a Flash Drive.
Windows CE and some loads of Linux will work though.

[Myrddin]

Reading the OS into RAM from FLASH, then executing without touching the FLASH again is a common strategy. Some embedded systems use EEPROM for persistent storage of custom values. That is the case with the PIC18F6680 that I use on my CAN controllers. The program memory is in FLASH. The application can use the EEPROM area to save tunable parameters such as node id, delay parameters and calibration values for the A to D converter.