As short side project I created an app that exports messages from the webOS 2.x and 3.x message database and writes them into a text file.
There were some people on the webosnation forum who asked for a way to get their messages into Excel: http://forums.webosnation.com/hp-pre-3/311205-sms-mms-transfer.html
Because they had some thousand messages my advices with command line stuff did not help them so much, so I figured I write a small app. The issue with the app is, that it needs access to the message db, which apps usually don’t get in webOS. To circumvent that issue, there is either a command line that you have to execute or you can install a patch. The app is published in the preware feeds: http://www.webosnation.com/export-messages
Also the code for the app is on github: https://github.com/Garfonso/ExportMessages
The patch has been submitted to the patch portal. But you can also download it from github: https://raw.github.com/Garfonso/ExportMessages/master/permission.patch
I hope that helps some people.