[Morgan Gillespie]

There is many ways to make soda bottles into a high flying AIMED rocket. These are the two coolest and easiest ways I know
Fill it 2/5 with water put it on a home made PVC launcher with rubber rings, hook it to an air compressor, wait until you can hold no more and let go. WOOSH! Altitude 200-500 feet. If you don't have an air compressor you can use a bike pump... Altitude 100-150 feet. With correct pumping timing & amount.
OR
Take a diet coke, empty 1/3 of it, dry that empty 1/3 with a tissue on a stick or something of that sort. With that same stick tape a bunch of mentos around the top of the bottle, lightly screw the cap on for 7/8 of 1 turn. Make a prop of a few bricks to keep it aimed up, turn it upside down and prop it against the bricks, RUN! WOOSH! Altitude N/A Feet

[note]You have to get the cap just right or it wont launch. If you cant drill a hole in the cap and turn the cap all the way on. If you cant even get that to work right, try the mythbusters zip tie method.[/note]