[the anonymist]

if there's no sim in the phone or it's unactivated, can the ipod function still be used?

if not, would jailbreaking do the job?

[Jeremy]

If it's never been activated then no you would not be able to use it as a iPod unless it's been activated at one time. Yes jailbreaking would do the trick. Just would need to activate it while jailbreaking.