This is basically a just a homemade water pump made from some things you might have around the house. Its useful for many things. This isn't my idea, so give credit to junits15.
What you need:
water bottle with cap
aluminum can or other metals you can cut
motor (one that spins fast?)
tubing (copper or other source...)
power source (3 - 9 volts)
hot glue gun
Step 1: Prepare the bottle cap
We only need the neck of the bottle. Cut the bottle near the top and sand it down.
Drill a hole in the middle of the bottle cap making sure its centered about the same size of the middle of the motor so it fits in. Drill a hole in the side big enough for the tubing going out. Don't forget to drill a hole in the bottle cap so the tubing can flow out.