If you want to view your iphone text messages on your computer or back them up before deleting there is now an easy way.
Update: A better solution has been found
Tansee iPhone Transfer SMS
iBackupBot for iTunes will let you access your Iphone SMS text messages and export them. You can even access all your previously deleted Iphone text messages if you synced with itunes there is a backup of everything stored on your computer and you can use this program view them and export them to a text file. There is a free 20 day trial with nag screens, but it can do everything you want to easily and if you decide you want to purchase the program you can. If it asks you to register just hit cancel and it will give you all the features.
You can also view/export contacts, notes, call history, pictures, and SMS Text Messages of course. This is the easiest software I have found for viewing my Iphone SMS text messages from my computer.