Obsidian Portal by now I'm sure, and if not well, I have to ask: what rock have you been hiding under? I cannot begin to say enough about how valuable this site has been for me and my gaming group over the past few months.
My friends and I have been playing DnD off and on together for years now. Of course, when we were growing up, we played weekly and sometimes more often than that, but as the years went on, and we all sort of went our separate ways, it became difficult to gather more than once or twice a year. Thankfully the internet came to the rescue. We decided to try a play by post method on our own private forum early last year and it has been very successful for us. Along the way, however, we've had to take a few periodic breaks, so game play has not moved as quickly as we would have liked. That's where Obsidian Portal comes in.
Shortly after we started playing on the forum, I stumbled upon Obsidian Portal and immediately signed up. After watching a few tutorials and checking out some other campaigns to get a feel for the tool, I decided it would be perfect for me as the DM to organize the adventure. My memory is terrible unfortunately, but as we played on the forum, I would update the campaign on Obsidian Portal. As we've taken several breaks along the way, it has proven itself as one of the most valuable DM tools I've ever seen in my years gaming. Without this site, I would have forgotten much of what occurred along the way after our many breaks in the game. Sure I could have slogged through hundreds of posts on the forum to get caught back up, but the idea of that is frankly overwhelming.
Now, with Obsidian Portal, we can take a break for two months, come back, and not miss a beat. I've even found a way to get the players involved in the process as well. To replace the table top sessions of role play, I encourage them to post their own entries to the adventure log on the site. The results have been fantastic so far and really has helped get the players more involved in the campaign and their characters.
Also, Obsidian Portal can be used in a variety of different ways, but the trick is learning how to utilize the tools on the site. There is a bit of a learning curve, but by investing a couple of hours into really learning how to use the tool, you can save yourself from major headaches down the road. There are many fine examples of the tool out there, but if you'd like to see how we've used it thus far, head on over and take a look at my campaign.