I just downloaded an app for my iPhone called WhatsApp.
It is a Smartphone Messenger which allows me to replace SMS and chat directly with my friends and contacts. This app even tells me when somebody is typing back a reply!
WhatsApp integrates seamlessly with your existing phone Address Book and there is no PIN or username to remember.
Get it now from http://www.whatsapp.com/download/ and say goodbye to SMS.
I Tego Arcana Dei