> Problem with EEPROM is 10*6 write cycles typically (for Microchip parts).
> It depends on how often one needs to write. Every 10 minutes would be no
> problem. But every second could be.
>
> What other storage options are open to PIC users for extra memory?
> Philips has a 256 byte static ram chip with I2C. But are there other
> serial static ram chips? One poster suggested using static ram chips such
> as are used in PC cache memory systems, but
> I suspect these would be messy to interface to.

RamTron makes some nice I2C parts: 512x8 and 2Kx8 "FRAM"'s.  These things
are amazingly cheap (under $3/2K I think) and work like EEPROMs except:

[1] No delay on writes; as soon as the data is done being written to the I2C
    bus the chip can read or write more data. (i.e. writes take about 20us
    instead of however-many ms)

[2] 10^12 endurance.  Note, however, that the chips are worn out by both reads
    and writes (the 10^12 limit is for total cycles).  On the other hand,
    even at 1000 accesses/second to a location, it would take 31 years to
    wear out the part.  [hopefully I'm remembering the 10^12 right]