Is there a quick way to ID the phone?

Hi,

Is there a way for the SDK to identify the phone - say the IMEI number or something similar?

A session ID or token of some sort may work but I would guess this may change over time/sessions?

I would be looking to set an element in the model to this ID - and have it saved back to the server.

Alternatively, if  that isn't possible, when a user logs on, and no 'local' ID exists, could either the server or phone app create an ID and have it saved locally - and have it persist until some kind of intervention (rather than time out etc)?

Thanks