I am using a Squeezebox 2 connected via TOSLINK to the F80. You will need a TOSLINK to Mini jack fiber cable to connect to the F80 digitally.

I use the Van Den Hul TOSLINK to Mini Optocoupler cable. It is one of the better TOSLINK cables and sounds fine.

Alternatively, I believe Apple's web site sells a TOSLINK cable with a mini-jack adapter.