If you're looking for ideas, I'd suggest a few of the following:
Create a sports bar environment at home by having TVs on in all of your gathering spots (i.e. living room, kitchen, rec room and yes, even the bathroom!)
Tailgate before the big game in your driveway. Ask your friends to bring their own meats for grilling and set up a few smoky joes and gas grills. You can provide the side dishes. Everyone can picnic on their tailgates or around a picnic table or on blankets on your lawn.
Make up a variety of fun "bets" such as which team will score first, what the point spread will be at half time, who will score the first TD, how many field goals will be kicked in the game (total), which team will rack up more penalties, etc. Have betters put in $1.00 or desired amount for each item they're betting on and whoever wins takes the pot.
Karaoke half time show. Set up your karaoke machine in the living room and take turns putting on your own show. That could be quite entertaining, especially after a few beers.
If you have enough room, set up cones in your backyard and have "field goal" kicking contests at half time. Players can draw cards to see how far they have to kick it (i.e. 10 yards; 25 yards; etc.)
Ask everyone to bring their favorite dip. You provide the chips and veggies. You might even have your own "Super Bowl" party where everyone brings their favorite chili recipe. You provide the corn bread toppings (i.e. shredded cheese, diced onions, sour cream).