>> What would be cheapest and still reliable hardware
>> solution to support ICSP in high volume manufacturing ?

Hmm.  Are there any bootloaders that permit themselves to be 
overwritten?
The idea would be to pre-program all your PICs with the bootloader, 
thereby
getting more flexibility in comm links for additional programming.  
(and if
you don't NEED that last bit of memory, you wouldn't have to overwrite 
the
bootloader, but the space would be available...)

BillW
-- 
http://www.piclist.com PIC/SX FAQ & list archive
View/change your membership options at
http://mailman.mit.edu/mailman/listinfo/piclist