We have one touch installs for XMB, PHPBB, and Invisionboard. Here are some links to some conversion scripts:

For PHPBB:

http://www.phpbb.com/downloads.php#converters

For XMB:

There are none that I'm aware of. (support for XMB isn't the greatest from their community)

For InvisionBoard:

http://www.invisionboard.com/?resources

This way, you should be able to convert to something faster and more efficient without losing your existing database. :)