Can I put other unlock phones on the iPhone acct?

You want to change your iPhone sim to your unlocked Nokia?In general for any phone to swap networks...it should not be locked with a particular network.If it is, then it will not accept other networks.One can unlock it using the service provider or third party unlocks like Unlock-free.com where they offer free unlocks for basic mobiles.Since you have an unlocked phone...there is no problem...you can swap networks.