An e-cigarette or e-shisha as they seem to be known these days, with the resultant glycol based "smoke" (actually a vapour) drifting through my beard.
These devices have evolved considerably since they were first introduced as a safer alternative to smoking. They work in the same style as a fog machine by heating a smoke fluid based on water and glycol. The fluid travels from a reservoir up a wick which has a heating wire wound round it. The glycols commonly used are vegetable glycerine or propylene glycol, and flavours and optionally nicotine are added if desired.
I don't smoke, so I use the nicotine-free fluids.
These devices have incredible geek value and are not only cheaper for smokers to use, but also significantly safer, since they are just breathing a vapour. The fog generated is exactly the same stuff that clubbers have been exposed to in nightclubs for decades with no known adverse effects.