i suppose it is posible, i have thoight about ripping the falsh chips out of a ipod nano and using them as they are just a higher capacity chip (pin compatible)
the only thing you would need to do is flash the new chip with the image of the c3000, linux should detect the full sized chip so that once you boot into linux you can use the mtd chips to repartion the last partion to fill up the remaining flash
flashing the chip would be the hard part, however if you are intrested you could probelly by a faster flash chip (about twice the speed) and give that ago