I've done that a couple of times.. I got a bunch of easteregg shaped gumballs one year for easter, and they were starting to get a little old so I decided to chew up as many as I could and then just get rid of them. So after going through most of the carton, I had this enormous wad of sticky gum in my mouth, giving my saliva the consistancy of glue. A couple of minutes after I'd spit out the gum I hiccupped, and ended up sucking a long string of this thick, syrupy goop into my windpipe.
It's funny in retrospect, I ran to the bathroom making this horrible noise trying to clear the crap out of my throat, my mom runs in and tries to give me the heimlich manouver, so I have to throw her off before I could get to the sink for some water.
The same thing happened to me in class once too.. skittles and cherry coke are a lethal combination.