Ah, April 1st, easily one of the most fun days online, as literally hundreds of websites post gags-a-plenty. Here’s a quick listing of what I’ve liked so far…

• Google Australia announces g'Day with MATE, which allows you to Google ahead one day in the future.
• Google USA announces Custom Time, which allows you to set the time an e-mail was sent, so your e-mails never appear late again.
• ThinkGeek offers a handful of fake products, including a caffeinated cereal, WiiSports for the iPhone, and a BetaMax-to-HD-DVD converter.
• YouTube's front page has every single featured video going straight to RickRolls.
• Popular Webcomics XKCD, Questionable Content, and Dinosaur Comics have swapped URLs for the day.
• YTMND has announced they're shutting down, but oddly enough, the HTML has a hidden message saying this is not an April Fool's gag. We'll see, I suppose.
• [adult swim] got into the act by broadcasting what is apparently a rough cut of the first episode of The Venture Brothers Season 3. They typically do a more over the top gag on April 1st proper, so we'll see what airs tonight.
• Google gets us again with Virgle, an attempt to populate the moon.
• The long-winded ARG for The Dark Knight continues today with Clown Travel Agency. Could this lead to a new trailer?
• Blizzard Entertainment perhaps wins the award for the most ambitious series of April Fool's Gags, as they announce the long awaited console port of World of Warcraft, The Molten Core; a new class in StarCraft II; the official Diablo Loot Pinata; and a rather rockin' new class for WoW.
• Docs.Google.Com allows you to create paper airplanes!
• Microsoft has a slue of great new XBox products available.
• City of Heroes announces VISUAL SOUND!
• IGN whoops EVERYONE's ass with this unusally well done Legend of Zelda movie trailer.