(Note: Castile soap looks expensive but, because you use it in such tiny amounts and it can replace nearly all the other cleaners in your house, it is actually a good value for the money!)
Technically, you can use this stuff to clean almost anything - it's completely safe for pets and children, and an excellent disinfectant! Specific ideas and ratios follow, however:
Hand Soap: Take an empty foaming handwash bottle and put a couple squirts of Dr. Bronner's Castile Soap with water. It foams up just like the stuff you buy at the store.
Soft Scrub: Mix with baking soda until it's like a runny frosting consistency. I use this mixture for cleaning sinks, showers, anything where a little abrasion is needed. It doesn't scratch and it rinses away easily.
Fruit/Vegetable wash: 3 dashes in water rinse most sprays off fruit & vegetables
Pest Spray: Mix 1/4 oz of soap in 1 quart of water H2O. Apply to plants to keep away pests.
Floors: You can mop almost any type of floor with a solution of ¼ cup liquid Castile soap and 2 gallons warm water. If the floors are greasy, add ¼ cup distilled white vinegar to the bucket.
Leather upholstery: Add 2 drops liquid Castile soap to 1 quart warm water. Apply to the leather with a barely moist sponge.
Marble counter-tops: Stir 1 tablespoon liquid Castile soap into 1 quart warm water. Dampen a cloth with the solution and wipe surface. Rinse, then dry with a clean cloth.
If you're feeling really adventurous, you can use a few drops of Castile soap in place of toothpaste or make your own shampoo (1/4 cup of castile soap,1/4 cup distilled water, 1 tsp olive oil and (optional) 1 tsp glycerine).