I know that it doesn't pay to assume anything, so I'm asking if you sanitised the fermentor before adding the hot wort. Always a great idea. Not being nasty here, just asking because it wasn't mentioned, and in case it's something you hadn't considered.
And, in the same vein, do you disassemble your tap and clean it thoroughly between brews?
Apart from that, it seems reasonable to suggest that you put some metho or cheap vodka in the airlock, and then plug with some dry or Iodophor-soaked cotton wool. Dry cotton wool should be OK if using alcohol in the airlock. Then screw the lid on tight, to keep the beasties out, and the only way they can get in is through the alcohol-filled airlock.
After all that, I'd recommend to pitch yeast within a couple of days of wort creation, to minimise the chance of contamination in a pseudo-sanitary set-up.
For a fair bit more confidence in your sanitation, use a cube/ jerry-can for a true no-chill.
To reiterate what others have said in many, many threads before: please search for more info on this site. I'd suggest reading more of the no-chill thread, or the no-chill spot in the wiki when/if someone puts it together, and the "no-chill in a fermenter" thread.
Best of luck with the next one. That's gotta put a huge dent in your enthusiasm for all-grain. A poor result with my first all-grain, due to a lack of proper equipment delayed my venture into the depths of brew-mania that comes from grain brewing.
Beerz
Seth