Hi!
It is possible to use just 2 PIC pins for I/O. I did it implementing a shift register for reading keys and another for writing to Nokia 3310 LCD. Take a look at http:/parsek.yf.ttu.ee/~felc You find an unfinished soldering station project with PIC12F675 with schematic and assembly code. Comments are in Estonian but i hope you understand the code
rgds,

/Felch

PS. It IS a little bit slow routine but it works.