How to block a stolen iPhone?

Its not possible, sadly. You can call and cancel the contract but all the thief will have to do is get a new SIM card and they'll have a fully functioning phone.

Also note, if you did not set a passcode, then the user has full access to any email accounts, your browser favorites/history that may be to sites you told it to "remember you" etc when around WiFi (assuming you already canceled service to it via cell).

Even if you did have a passcode, they could maybe guess right over time.

So would be best to change all your email account passwords that your iPhone was checking. And changing the password to all the websites you may of visited on the iPhone. And while at it, change your iTunes password.

First I would contact your provider. 2nd you should still have the serial number of the phone with this you could contact apple and let them know the phone was stolen. There is a site if I can find it that allows you to post serial numbers for things that were lost or stolen. *http://www.stolen911.com/index/listings/category161.htm* Hope this helps

All mobile phones have a unique IMEI number, service providers can block mobiles across all networks using this number.

To get it on any phone type in *#06#
Or on iPhone Setting > General > About - IMEI

You should make a habbit of noting this number down and keeping it in safe place to give to service providers in case your mobile is stolen or lost.

Hopefully someone will come out with a program similar to this for Windows Mobile:
http://www.scpsoft.com/
remotePROTECT (by way of sending a text message to your phone) remote wipes, locks, unlocks, tells you if the simcard has been changed and if so to what, etc. I lost my WM phone once and in less than five minutes I locked the phone by just sending a text, and then minutes later fully wiped it (including the sd card).

Too late for you, but 2.0 is supposed to have a remote "wipe" available. I don't know if the provider does this or if you can.

The remote wipe feature included with 2.0 will be available to an Exchange admin for an Exchange account only, and will likely require having the business unlimited data plan.

I did not know that. Bummer. I thought that was a great feature of 2.0. Oh well, maybe someone will create an app that lets you do that. I mean its your phone, you should be able to so like the other guy did on his WM phone and send it a text message that tells it to "wipe" itself. Thanks for the info.

You should use the Passcode lock feature with your iPhone, and use a SIM PIN or SIM lock .

I use the following settings.

Auto-Lock after 2 minutes.
Require Passcode after 5 minutes.

Yes this requires that I enter my passcode after my iPhone has been locked and not being used for 5 minutes, but if my iPhone is lost or stolen, this should prevent someone from accessing anything on my iPhone unless they pick it up and use it within 5 minutes after I used it last.

You can also set the require passcode to after 1 minute, or immediately.

The passcode is also required when powering the iPhone on to access anything on the iPhone, followed by the SIM PIN or SIM password to activate the SIM card and use and phone functions.