hahahaha... ok here's something that's fun and easy to do and is great for night time...
take a big bucket fill it with water
put a bottle in the water(dont get any water in the bottle)
put some of the works inside, you only need about 2inches at most, the bottle and fill up with little balls of alluminum foil and quickly...
put a big balloon over the top
you now have hydrogen gas.... stap a very long fuse to it and let it fly way up and it explodes... descently loud and a big flame...
the water keep the bottle cool so you wont burn yourself because it usually produces more gas for more than one balloon.
optional: attach hose from bottle to another container filled with water hose entering near the top and going down. the water will filter out the... i think it's chloride that's in the gas and you'll get a more pure hydrogen that is very loud
also... this is called a works bomb when you fill a two liter bottle with it and throw it... no fire but a very loud boom... works amazingly with 5gallon buckets