This is a very simple and cool trick to cleanly cut off the top of a soda can to make a cup or some sort of container (perhaps a safe).
Step 1: Gather Materials
All you need is a soda can and a can opener.
Step 2: Cutting
Line up the can opener on to the rim of the soda can as shown. This is where the cup or container part comes in. If you want it to be a container, leave the little bit of aluminum in the rim uncut like in the second picture. If you want a cup, cut the thing clean off, all the way around. With the container, you can open and close the whole lid. With the cup, the top is wide open.
Step 3: Rinse
Don't forget to rinse any excess soda out of the can.
Step 4: Extra
The cup version of this also works decently as a desktop pencil holder for school, the office, or at home.