SMS Touch [iTunes Link] enables users to compose SMS messages using Apple’s wider landscape keyboard and send them through email without incurring SMS fees. These messages are sent through your email program but arrive with the recipient as SMS messages.
Users can compose a text message in SMS Touch and then select the recipient’s mobile phone number from their contacts. SMS Touch generates an email message that is properly addressed to arrive with the recipient as an SMS message. When the recipient replies to the text message, the reply arrives in your email inbox.
At $5, this application may seem pricey but it could save you quite a bit of money in long run.