I've written a IB3 -> phpBB2 converter in vbscript. Windows users are in luck. I'm not sure about mac users but hey, worst case just go over to a friend's house and run it on their pc. Basically you make a tar backup of your IB3 database, download it to your pc & unzip the tar backup, run the vbscript, and then upload the converted output into your SQL database. Read the instructions at the top of the script for more specifics.
Download the latest version
If you are unable to make a tar backup of your IB3 database AND your database is mySQL, please contact me via PM if you would like to test a tool that will create a backup from your mySQL database.
NOTE: If you previously ran the converter and are having problems searching your forums (more specifically, topic titles), download the zip file above, extract the file "rebuild_search_tables.php", upload it to the folder phpbb is installed in, and then run this php script to rebuild the search tables.
Please note that many of the user comments in this topic are no longer applicable. If you are having problems, I recommend reviewing the converter instructions.
Yes, it converts Ikonboard 3.0 RC 2, 3.0 RC 3, 3.0.x, 3.1.0, and 3.1.1