I am pretty sure you can make it into tomato sauce by just adding enough water. So if you want to make pizza sauce and only have paste, warm it with enough water to make it saucy and simmer with seasonings.
You can make sloppy joes with tomato paste, too. I use TVP, fried onion and pepper, tomato paste, water, brown sugar.
You could probably make some yummy, saucy tortilla filling with tomato paste and meat or tvp and the right spices.
Not just plain tomato soup, but tomato soup with macaroni and beans - pasta e fagioli.