This is what we found on Wikipedia regarding the The LOL Podcast:

LOL, or lol, is an acronym for "laughing out loud", and a popular element of Internet slang, which can be used to indicate amusement. It was first used almost exclusively on Usenet, but has since become widespread in other forms of computer-mediated communication and even face-to-face communication. It is one of many acronyms for expressing bodily reactions, in particular laughter, as text, including acronyms for more emphatic expressions of laughter such as LMAO ("laughing my ass off") and ROFL or ROTFL ("rolling on the floor laughing").

In 2003, the list of acronyms was said to "grow by the month", and they were collected along with emoticons and smileys into folk dictionaries that are circulated informally amongst users of Usenet, IRC, and other forms of (textual) computer-mediated communication. These acronyms are controversial, and several authors recommend against their use, either in general or in specific contexts such as business communications. The Oxford English Dictionary first listed LOL in March 2011.