I just came across a site that is remarkably similar in concept to becontrary.com, called convinceme.net. I don't think it existed when I started work on my site. Like becontrary.com, they have dual columns for arguments and voting, but it is more competitive than my debating concept, which about arguing purely for the hell of it. They also have a slicker looking design, obviously created by a real web designer rather than a coder working on it in his living room. Oh well. I guess competition isn't necessarily a bad thing!