It's a useful tool. It can express genuine amusement, sometimes in an "I shouldn't think that's funny" kind of way, it can express derision, it can convey "I'm in on the joke" ... I think it's a snickery snort.
When I was asked about it there, somebody urban dictionaried it.
1. snork
Verb: to drink something and have it come out your nose because you're laughing so hard.
I told her a funny joke while she was drinking a soda and she snorked. Then I killed her for wasting good soda, and licked it up off the ground.
2. snork
to unintentionally snort loudly while laughing. Also used as an exclamation after someone snorks, to emphasize the fact and increase their embarrassment.
She laughed so hard she snorked.
After he snorted, I pointed at him, yelled "SNORK!" and laughed.
Oh well. You can't expect urban dictionary not to throw a little misogyny into whatever ...
Oh, hey, this is the good one:
5. snork
A word occasionally used on forums in reply to a very funny post, it is sort of like posting "LOL" or similar. (but cooler)
I am kewl, so kewl.
Snork.