This app allows you to send free text messages from your iPhone. Nifty app which just uses data.

<a href="http://www.txtdrop.com/iphone/#_sms" title="Free Text Messaging for iPhone" target="_blank"><img src="http://www.modmyi.com/images/apps/textmessaging.png" border="0" height="354" width="320" /></a>

<a href="http://www.txtdrop.com/iphone/#_sms" title="Free Text Messaging for iPhone" target="_blank">http://www.txtdrop.com/iphone/#_sms</a>