I was wondering if anyone had any experience integrating the user db's of XOOPS and phpbb so that users wouldn't have to register twice. I'm using the latest version of XOOPS and phpbb 2 but any info I can find on this uses much outdated versions, any help would be greatly appreciated. :)

There was a hack available from www.bbpixel.com for this. It may be available still.

However, it did require to be updated regularly, with any XOOPS core changes.

The author of one of the most recent versions, M0nty, is currently working on scripts to transfer from many bb systems - to CBB - to make it easier to take an existing forum and move to CBB instead.

There's a post on www.xoopsforge.com with one of the earlier versions, for x-ipb