Roger (from the French part of Switzerland)

What PIC are you planning on using? How are you planning on getting the update in to your cellphone? MOST phones (including Nokia) don't like to receive file extensions they don't know about (for security) so generally receive them and hide them, or reject them. You COULD make a MASTER programmer which uses IrDA or RF or whatever, and then you won't have to worry about the complexities of having different chipsets trying to chat with eachother.

ALSO remember that if YOU can use a cellphone to upgrade a PIC using "point and shoot" (I assume you are looking for some kind of commercial application) then I can use a cellphone to rob your information, AND I can use a cellphone to sabotage YOUR product.