Having been given permission from Andreas, I'm just writing a quick post about the new OOOL (version 1*) that is included in OOTP12.
In previous versions of OOTP if you've wanted to join an online league it's either been by word-of-mouth or visiting the Online Leagues forum to see if people have posted in there or updated their entry on the IOLD, but with OOTP12 such information is available from the front screen.
If you're a current online league commissioner who wants to put their league on the system, or a GM who wants to find a new league the OOOL makes it easy.
When you open up OOTP12 you will have a menu option that lets you register on the system and as a GM this will allow you to search, and as a commish this will allow you to join.
I've written up some brief instructions this afternoon for this as the manual is a work in progress and it'll be good to get this going with as many leagues as possible.
The instructions are available
here
The OOOL directory will evolve into an even more complete system as patches and updates occur.