I know a few of you on this forum work for a provider's CS department so I was hoping at least one of you might be able to answer this question. When setting up a GSM phone with a carrier (Cingular in this case) you are asked for the phones IMEI number. I understand that the provider may download information to the phone - I've been told a number of times to cycle my phone on and off at least once a day for this reason, and that is one of the reasons that they need to know the type of phone and the IMEI number. Now for the real question(s). The phone I have listed with my provider is one of a few GSM phones I use. Since each of the phones has a different IMEI number does this cause any problem with the provider when I use one of the non-listed phones? Will I still receive downloads? Besides checking to see if the IMEI number is blacklisted, why does the provider care about the IMEI number? What purpose does it serve? Does switching phones cause any problems with the provider Thanks!