Q: apple ID on multiple iphones/ipods

If you want to use separate iTunes accounts on them (you could use the same account on them, especially if you want to have the same iTunes purchases on them) then you will need a different email address for each account - each iTunes account has to have a unique primary email address.

Creating an iTunes account : http://support.apple.com/kb/HT2731

Creating an iTunes accunt without giving credit card details : http://support.apple.com/kb/HT2534