What can you do with an empty soda bottle?

Call this a spinoff from this thread: http://grassrootsmotorsports.com/forum/tech-tips/fab-a-funnel/75313/page1/

So, aside from refill it with liquid or place in the recycling bin, how do you reuse old plastic soda bottles?

http://www.youtube.com/watch?v=Q0_4qFrxw_4

A hat, a broach a pterodactyl!

Fill with liquid nitrogen, tighten top, throw.

https://www.youtube.com/watch?v=_zMAWztZ6TI

Radiator overflow bottle.

They make a pretty fair silencer for a 22.

Duct tape to barrel, pull trigger, done.

Back when you could still get glass bottles, at the weekly bush party, we'd fill an empty 26 oz Coke bottle with gas, put the cap back on, and get the drunkest guy to set it in the middle of the bonfire. It was always a good time.

I'm guessing these responses aren't what you had in mind.

Make a full automatic air soft gun:

https://www.youtube.com/watch?v=_vRU6fcF6WM