half a block of tofu

If it's silken, make vegan chocolate pudding! I am by no means a vegan, but I really enjoy it and it turns out quite rich (almost like a mousse).

I really like making caesar salad dressing with leftover tofu. Alton Brown's recipe is the best one I've found so far. http://altonbrown.com/no-guilt-caesar-salad-and-dressing-recipe/

if you can get your hands on thousand year-old eggs (can be found in most asian/chinese grocery stores), i would recommend a recipe such as this: http://www.foodnetwork.com/recipes/silky-tofu-with-ancient-eggs-recipe.html

we make it all the time - it's simple, healthy, and delicious. we don't usually have or use preserved mustard greens on hand and it's still delicious!

Tofu salad with rice wine vinegar or miso dressing, scallions, and bonito flakes! Throw on some sesame seeds if you really want.

I would probably stir fry it with veggies or add it to fried rice.

Tofu will last several days immersed in water, no need to use it right away if it's the typical commercial stuff.

Or simply cube and add to salad with peanut or sesame or some other Asian-inspired dressing.

following Half Pint lead,
for regular - wrap slices in cheesecloth, then put between sections of old newspaper under a weight. press overnight. you'll get compressed sheets which can be used in sandwiches, sautes, salads etc. and/or frozen and then used for same.
for silken - can be pureed & used as a egg replacement in baking. or in a smoothie, for extra protein conten.

I like to add random leftover ingredients to soup. Miso, hot and sour, kimchee soup, etc

What kind? Regular or silken?

If you have the regular firm kind, you can crumble it and scramble with some onions, garlic, curry powder, and salt.

If it's the silken type, warm by covering with hot water for 5 mins, then drain gently, and splash some soy sauce, topping with thinly sliced green onions and bonito flakes (if you have any). Then dig in.