This was mentioned below in the comments but I figured it deserved its own post on the front page. Tonight's game will be broadcast on KDKA for cable folks in Allegheny, Armstrong, Beaver, Butler, Fayette, Forest, Greene, Indiana, Lawrence, Venango, Washington and Westmoreland counties, along with Monongalia and Preston counties in West Virginia and Garrett County in Maryland. For more details on whether you'll get the game or not check the Post Gazette. Nationally it will be on NFL Network.
If neither of those is an option you can watch the game online here . I have no idea what the quality is like, but its certainly better than nothing.
Another option which Ed Bouchette actually brought up was to order NFL Network and then cancel it tomorrow. The cable companies should charge you a pro-rated charge which would only amount to a few dollars. I don't know how well that will work so don't yell at me if you ended up getting charged too much. Enjoy!
Hat tip to Kirk B in the comments section.