A simple idea - include a field within each member's account profile for the phone/device IMEI number. This could either be entered manually by the member, or (preferably) auto-populated from a backend database (means it is always up-to-date)
When you lose your mobile and need to make an insurance claim or Police report, the IMEI number is needed. This can usually be found on the original packaging (you did keep it, right?) and on the original purchase receipt (you know, that really important piece of paper you put somewhere safe in case you ever need it - if only you could remember where you put it!)
If you have neither of the above, you then have to resort to raising a support ticket with an agent and waiting up to 24 hours for a reply, which can seem like an eternity.
By having the IMEI number stored within a member's profile they can simply log into their account to retrieve it.