The number one place to find pornography, hentai, message-boards that you can ruin or disrupt, free-to-add-definition dictionary websites that you can annoy, Invader Zim fan sites and me.
Purposeful, sarcastic misspelling of "internet". A term seemingly inspired bySomething Awful creation Jeff K, known for his indecipherable ramblings patterned after the habits of a stereotypical AOLer.
You can't check your e-mail? Is this your first day on the intarweb, or what?
Tongue-in-cheek reference to the Internet.
Etymology: Bastardized version of "InterWeb", which is a combination of Internet and the Web (which is in turn colloquial term for "World Wide Web")