Does Optical Audio input matter?

[desura]

Compared to a regular 3.5mm jack?

And, how do you actually hook one of those things up to like an iPhone? Or, you don't? And just power it through like a standalone cd player?

 

[LoveMachine]

Answers in order:
1. Better signal fidelity.
2. You can't.
3. Right.
4. What?

 

[NutBucket]

To expand. Very few consumer-oriented portable music players offer(ed) TOSLINK outputs and almost every single one was a CD player. I believe my old MD portable had a TOSLINK record capability but that was far from the norm as well.