Hello!
I also work on something like this, however, instead of selecting a webapp out of the bunch for user credential storage, or LDAP or whatever, I decided to use basic apache authentication that authenticates to the operating system (unix password) using pwauth. Mediawiki has a good plugin to use Basic authentitaction to auto create wiki users on their first login. I make all apps use this authentication data, so "single sign on" is working. What more, it is running behind https - it was a must in our case.
However, I don't know if phpBB and others could use basic auth info from apache ($_SERVER['REMOTE_USER'] ..or what)
Good luck Robert
I recently set up a large collection of web apps with an ldap directory backend - included in this was phpBB and MediaWiki. However, I didn't get the single sign-on bit of it working, neither was it one of my original targets.
2009/4/16 Paul C Lustgarten plus@research.att.com