One yummy thing to do is to cut firm tofu into cubes (1-inch or smaller), dip them in soy sauce, powder them with fresh-ground black pepper and bake them at 350 degrees (farenheit) for 20 minutes or so. (I don't generally time 'em - just check to see if they're chewy yet)
This not only changes the texture of the tofu to something more meat-like (if that's your goal) but it also gives it a spicy flavor that goes really well in thick stews for the bigger cubes, and tiny ones go great over salad.