This meme originated in Facebook, in a form of groups.
there are many variations, and this is quickly becoming the new can this x get more fans than y.
it is notable as each group has many thousands of fans.
i think this is vastly expanding, and will become VERY popular.

LOL jk (jk meaning joke or just kidding) is used to lure your reader into a false sense of security, thus making them laugh afterwards. similar to the NOT! joke.

some example are:

Hey! i found nemo! LOL jk hes dead.
PISS OFF! LOL jk i luv ya rly.
I'd swin the ocean for you! LOL jk my turban would get wet.

thanks for reading!

some pages:
http://www.facebook.com/pages/gonna-get-drunkkkkkkkkkk-this-weekend-LOL-jk-im-muslim/109335759107342?ref=search&sid=100000404710060.3646536632..1

http://www.facebook.com/pages/Thats-what-she-said-LOL-jk-she-didnt/118738474815496?ref=search&sid=100000404710060.3646536632..1

http://www.facebook.com/pages/I-would-carry-you-to-the-moon-and-backLOL-jk-your-fat-and-id-die/109641345726589?ref=search&sid=100000404710060.3646536632..1

http://www.facebook.com/group.php?gid=122986861051556

http://www.facebook.com/pages/if-you-fell-id-catch-you-LOL-jk-youd-crush-me/107589732607015?ref=ss

http://www.facebook.com/pages/Id-climb-Mount-Everest-for-you-LOL-jk-Id-get-frostbite/100231110018895?ref=ss

and MANY more if u search deep