Radio KoL is a Shoutcast station created, owned, and operated by Kingdom of Loathing players. It broadcasts 24 hours a day with DJs from around the world, offering many different styles of shows; its schedule can be found here.
Radio KoL shows often include contests and giveaways. Jick created the Radio Free Regalia and Radio button candy specifically to be given out as contest prizes by the DJs. For Radio KoL's two year anniversary, celebrated on July 7th, 2006, the Radio Regalia was retired and replaced with a special series of six accessories (the Radio KoL Antenna Ball, Bottle Opener, Flashlight, Keychain, Maracas and Patch). Most DJs accept and even encourage player donations towards these prizes, and have "contest multi" accounts so that they can accept donations even while in ronin or hardcore. However, the purpose of Radio KoL is not to give you free stuff. If you enter the /radio channel asking when the next contest is, it is likely that you will annoy the DJ into not holding one at all!
Radio KoL upgraded its servers on June 12th, 2006, and moved to a new server host: a 150-slot 24kbps server and a 150-slot 64kbps server. While 300 radio slots is generally more than enough (the station hovers between 60 and 120 listeners, depending on the time of day), the regular shows hosted by Jick and Mr Skullhead require extra listener slots. Many players help out in this respect by creating server mirrors.
Radio KoL pays its server bills solely through listener donations, with a donation link on its website. The website is also where you can find the Radio Forums, DJ biographies, information on how to become a DJ, and (coming soon) Radio KoL schwag.
As well as the /radio chat channel, there is also an IRC chat on irc.synirc.net by the name of radio-kol. While not all the DJs go there, it is still another place to go to discuss the radio with other listeners.