Oh dear. This is such a silly thread.
I'm afraid the rep you spoke to tragically misunderstood your question, or doesn't know what he/she was talking about. At this point, you categorically cannot add events to the calendar on an iPod Touch.
Apple removed the ability from the list of things you can do with the device on their site. Apple removed it. Apple. The people that make it. They said you could do it, and then they removed that line. Because you can't do it.
Amazon is displaying the original press release specs that Apple removed from their own sites this week and replaced with the current ones. You think Amazon will know more about this product than Apple? That the models they'll ship will magically have the ability activated and Apple's won't?
Your sister's boyfriend's cousin that read on his best mate's blog that someone told his uncle's boss that he'd read on an Apple forum that an Australian Apple Store rep told someone that you could add events - is wrong.
Finally - do you see the screenshot of the iPod Touch's Calendar app on the front page of this very site - the screenshot that shows no + button? Please show me - where is the 'File' menu that your Apple Rep referred to?
You. Cannot. Add. Events. (at the moment)