Read in the NY Post today that there is a device that can retrieve deleted text messages on our cell phone's SIM card. Very Naughty.
Do any tekies care to comment?

A sim card is based on flash memory. Depending upon what and how much has subsequently been written to the card, deleted files may possibly be undeleted. You have to first relinquish physical possesion of your card though.

First, only GSM devices have SIM cards, meaning T-Mobile and AT&T users. Verizon and Sprint are CDMA technology which do not use SIM cards.

Second, most GSM phones by default store contacts and text messages on the phone itself, not on the SIM card. Storage on a SIM card is pretty simplistic. For example, only one phone number per name, though most phones nowadays will let you assign multiple phone numbers to a single name. SIM cards are also limited in memory. I remember having one that only allowed 25 pairs of names and numbers. So it makes more sense to store that stuff on the phone. Unless someone wants to use some specialized utilities, like possibly seem editors,  your deleted text messages and contacts in the phone's memory probably aren't retrievable.

So just make sure to save your text messages to the phone's memory, not to the SIM card. Or better yet, don't let anyone have your phone.