This definately falls more on the "tools" end of the spectrum, since many of these are decidely low-tech, but this article has some great suggestions for some unexpected uses for stuff you've probably got around the house.  I've used some before, and will certainly try others.  Some of my favorites:

22 Tenderize a roast by adding a peeled banana to the pan.32 Sprinkle soda in tennis shoes, socks, boots and slippers to eliminate odor.  42 Get rid of slugs in your garden. Put a shallow dish of beer into your soil buried up to the lip. The slugs will be attracted to the beer and become stuck in it. Empty the dish each day and replace with new beer as they are attracted to the smell.81 Keep brown sugar soft by adding a few marshmallows to the bag before closing it. 85 Repair fine cracks in china plates and cups can by boiling them in milk. The milk reacts with the kaolin in china and closes the crack. Place the plate in a pan, cover it with milk (fresh or reconstituted powdered milk) and bring to a boil. As soon as it starts to boil, lower the heat and simmer for about 45 minutes. There are 112 tips here, worth a quick read: Ordinary objects, super uses