Over the past three years or so, I have accumulated a set of backups of my text (SMS) and MMS conversations by using Carbonite's SMS Backup and Restore app for Android. Recently, I wanted to be able to actually look back on my conversations in a more organized form, so I built a simple Python tool called smsxml2html. It takes one or more XML backups from SMS Backup and Restore, and turns them into a series of HTML files, one per contact with whom you texted. It not only adds all of your SMS messages in chronological order, including a table of contents separated by month; it also parses your MMS messages and turns the embedded images back into discrete image files. Feel free to give it a try and PR the repo if you have any improvements! And be sure to back up your text messages.
Download/Repository
SMSXML2HTML: SMS Backup and Restore XML to Conversations
Download/Repository
SMSXML2HTML: SMS Backup and Restore XML to Conversations