I wonder how Farah's mission to eat on a budget for 4 weeks turned out. It would be cool if people who start interesting threads came back with an update. There are actually a lot of great ideas in this thread that I'm going to try just to save money on a regular basis.
Technically speaking, you could have meat for $1 a day from the dollar menus at most fast food places. I know people will frown on me for saying this, but in all honesty, in moderation it's not going to kill you. I like to get the whopper jr's with no mayo or cheese on days where I'm broke or in a hurry. Also, there is a sub shop called Dibella's Old Fashioned Subs, their large subs are like $8 but they pile so much lunch meat into them that you couldn't buy that much lunchmeat in the grocery store for that much let alone the ingredients to make the whole sandwich. And they're huge, I can cut them into 3 or 4 pieces and have them for a few days. Stir fry meals are a very easy way to stretch meat, plus there's many different varieties of them to try. Take a piece of top round beef and shave off a couple ounces in thin strips for each meal, it will go a long way. Canned tuna is great in spaghetti sauce, and even cheaper than using ground beef. Linguini in Clam Sauce is another easy one - just make sure you get the canned clams at the discount grocery stores, they should only be about a $1 a can.
You have already been given so many great recommendations! I would like to add that, along with couponing, check for marked down prices on meat. Our local grocery store marks down meat for a quick sale in the mornings. Ask around to see when your local stores mark down their meat for additional savings.