I couldn’t find any exceptional use of bbpress except the wordpress forums, any others?

Not far enough, but it is in use: http://pdmbc.com/phpBB/

The first level, the forum index is good, works well (once I fix the top nav), good navigation
The second level, which phpBB calls “view forum”, is missing navigation, no easy way back to the forum index
The third level, which php call “view topic” is poor, too busy, it does not need the right sidebar, there is no nav back to view forum or the forum index and my css in incomplete.

Three choices:
1. Fix it (which will take some fancy footwork inside phpBB as well as time to CSS right)
2. Replace the theme with a more standard phpBB theme (the easy option, but loses the value that was added by the right sidebar)
3. Ditch phpBB and replace it with a more standards compliant BB like bbpress
or two others I was recently was made aware of by the Web Standards Group mailing list:
Vanilla and PunBB

The more I think about option 1, the less I like it. The CSS is the easy part, the difficult part is getting phpBB to do what I want. And after my experiences I will not be using phpBB for any forum I create in the future. So why develop skills is something I am unlikley need in the future?

Option 2 is admitting defeat, but it does resolve most of the problems.

Option 3, will destroy the exisiting data, but puts a more manageable solution and I can develop new skills I may use later.

I will talk it over with the people behind PDMBC and make a decision.

If you are crazy enough to want to look at the code behind it, download the theme and the modified phpBB files this is the painful part, you have to hack the phpBB files, so the theme can include other PHP files.

Cheers, Simon.

Did not know about bbPress until you told me. Looks like I will be spending this weekend investigating it futher, looks interesting though.

Matt Mullegwen wrote that as well and they seem to play reasonably nicely together.