picprog-1.8.1 works fine on AMD64 for me - here's the session transcript:
andrei@bender ~ $ picprog --output ofile.hex --pic /dev/ttyS0
Picprog version 1.8.1, Copyright �� 2006 Jaakko
Hyv��tti <Jaakko.Hyvatti@iki.fi>
Picprog comes with ABSOLUTELY NO WARRANTY; for details
type `picprog --warranty'. This is free software,
and you are welcome to redistribute it under certain conditions;
type `picprog --copying' for details.
CPU clock speed: 2010 MHz
/dev/ttyS0: id 0x0560: detected pic16f84a version 0x00
Device pic16f84a, program memory: 1024, data memory: 64.
Reading program memory,
reading data memory,
reading id words,
reading fuses,
done.
