Well... this is my first instructable so just go with the flow...
its a really easy and effective bottle rocket it goes like 60-70 feet in the air if you get it right. here are some pix of the one i made. it actually is easy so MAKE IT LOL!!!!

Step 1:

first you need your equipment:
1: PVC Stand
1: 2 liter bottle
1: bike pump
1: tire stem
1: roll of duct tape
and a source of water
if your tire stem fits perfectly into the bottle you don't need the duct tape cause all u do with the duct tape is make it fit.

Step 2:

first step is SUPA easy. fill the bottle to about the bottom of the label with water. you can go slightly higher than the bottom of the label, but DO NOT, AND I REPEAT DO NOT fill the bottle up more than a quarter of the way because if you do, then the water will not completely drain and come down with (not leathal but very fast) A LOT OF FORCE!!!!!!

Step 3:

next, put the tire stem on the bike pump and run it through the PVC stand. then put the tire stem into the bottle. then flip the bottle over on the PVC stand. the begin pumping. the water should begin bubbling. make sure no water is leaking out (if a little is that is okay). then keep pumping until it......... BLASTS OFF!!!!!!!!

Step 4:

the last step is to watch it fly!!!!! then you can do again and again and again. hope u have fun! you can add wings or stuff like that. its easy to make u really got 2 make it.