It seems I found a gadget news. If you like to play water bottle launcher and want to buy it that makes worth for you to play, then an RPG-7 PET Bottle Launcher, a $370 bazooka-like toy from Marudai in Japan, is a perfect gadget for you. It lets you do a shoulder-mounted take on a classic middle school physics demo. Just Pump out the water and get ready to get some blow. You can also put the message to the bottle. Here is the video I found:
You can watch it again and read some explanations on:
Be Advised, this gadget uses for play only. Never use it on a false actions or you will regret for the rest of your life.