There's so much to love about watching sports, from the nachos, to the buffalo wings, to the grand slams, though that assumes you managed to find a Denny's with a TV. Getting you back in the game itself: GameSlam.
Just out of beta in time for opening day, GameSlam's a Chi-designed gaming platform that syncs up to live sports broadcasts and allows the user to engage with the game via real-time predictions, though only with regard to the players, so no points for accurately predicting you're about to run across the field with no pants on. Accessible via their website, Facebook, and, very shortly, mobile platforms, GS's direct data stream from MLB contests rolls in a few seconds before the cable delay, allowing them to coordinate a live webcast on which you can predict everything from the big picture (e.g., the Cubbies will win!), to minute details like balls & strikes, which is nearly impossible when international singing sensation Enrico Pallazzo is behind the plate. Correct predictions earn points, which can in turn be redeemed for stuff like virtual trophies and entry into tournaments, plus advanced users can even set up leagues or challenge their friends with head-to-head wagers, the real gamble being you'll still have any after watching this much baseball.
MLB is the only sport the game supports for now, but rest assured they've got plans for the likes of the PGA, the NFL, and the NBA, which can be hard to stomach if you're only in it for the OJ Mayo.