what's the first thing you got to do when lost a cellphone?

Have the sim card blocked by your provider. Also, let somebody know at once and let that person spread the news that you lost your phone.

in my mind : 1. call the operator to block their number and access. 2. maybe you must be watch about your number credit card or pasword (several of us, like to write any privat notes in cell phone). 3. Call the police about your cell phones 4. if optional, maybe you have to call your cell phones (fortunaltelly, if a good guys which found your cell phone)

oh my! sorry to here that!. try to retrive you friends numbers if you memorize some of it try to get another sim and start storing their nos.