Dang... This is HARD!!
First, the honorable Mentions... which should be practically everyone:
ADDGWC, Don that is, should get several but my favorites are "Whoa!!! you found my G spot!!!!" and " this Hitachi kicks A$$!!!"
AlbertP staying in the same X-rated vein with "JimmyD demonstrates the secret behind squirting."
Macmaam's play on Steven Hawking, "After Darrel adjusted the microwave, he began to notice that the entire universe was being sucked in through an upstairs window."
Both of Shortie's were excellent but I favor, "The Fires the other way"
Nerrak had some ringer's but he setup our Caption Challenge #5 winner with, "AaaaaChhhhhoooooooooooo!!!!!!"
Aaaaannnnd the winner is... TSP with, "Gesundheit". 
You just gotta love simplicity. Alright, A Karma to TSP for winning and a PM to get going on #6!
By the way, Lisa (Macmaam) was the only taker on the extra credit and she was actually very close... you know something about firefighting Lisa?
What's happening is called 'hydraulic ventilation', it's a technique for clearing smoke in a burning structure... in this case, which is a training burn, they used it to promote the fire by supplying it with more oxygen... they'd put the fire out (mostly) and crank it back up again by ventilating.
Go TSP!
Chip