I search in vain so far on Internet for definitive answer to my question: How do you erase your mobile phone data (numbers, messages, etc....) permanently so your data cannot be recovered with utilities such as Mobile Phone SMS Recovery.

There is (manufacturers) instruction from Wireless Recyling (http://www.recellular.com/recycling/...er/default.asp) that suppose to erase data in your mobile phone, but it doesn't explicit state that the data are erased permanently or not.

Without a definitive answer to this question, the only thing that one can be sure to safeguard the info is to completely destroy the SIM and the phone itself.