Clear SMS Messages

To clear the conversation but leave the header use the Clear button
inside the conversation. This works like a favorites list of people
you regularly text.

To delete the header too use the Edit button on the main SMS screen.

Archive Text Messages 

Your iPhone stores thousands of text messages. This seems like a lot until you realize how quickly a few threads fill up with hundreds of messages each. If you're on Mac, there's a nice little freeware utility called SyPhone that archives your SMS messages for you. Once you start it up, it will back up your iPhone's SMS messages through a helper app, so you don't even need to think about it. When you open SyPhone you can view all these messages in threads like on your iPhone.

SyPhone works by copying the messages from the backup of iPhone that iTunes makes each time you sync, so make sure you've recently connected before deleting new messages you want to save.

Exporting Notes

It seems limited that all you can do with your notes is to send them in an email. But this systems is very workable:

• To send your note to someone, email it.
• To export it to your desktop, email it to yourself.
• The first line of your note conveniently becomes the subject of the email.
• If you want to make your note an SMS, copy and paste it. Keep the 160 character limit in mind.