Keys has organized a group of famous people to sign off of Facebook and Twitter on Tuesday for World AIDS Day. They have agreed not to tweet or status-update again until $1 million is raised for Keys’ Keep a Child Alive charity.

Participants have prepared their “last tweet and testament” and will appear in coffins representing their “digital deaths” for videos and ads to promote the cause.

Jennifer Hudson, Ryan Seacrest, Kim and Khloe Kardashian, Elijah Wood, Serena Williams, Janelle Monae and Swizz Beatz are signed up to sign off of Twitter and Facebook.

Keys (who has 2.6 million Twitter followers and 7.8 million people who like her on Facebook) told the Associated Press, “This is such a direct and instantly emotional way and a little sarcastic, you know, of a way to get people to pay attention.”

Keep a Child Alive co-founder Leigh Blake added, “I have a feeling that Gaga is going to raise it all by herself.” (Gaga has 7.2 million Twitter followers and 23.9 million people who like her on Facebook.)

While an iPad out in the wild–held up by Stephen Colbert–got a lot of ink, here’s a video from last night’s Grammy Awards, which went all “Avatar” during a tribute to the late Michael Jackson–when a panoply of belt-it-out singers performed one of his posthumous songs with a 3-D twist.

In fact, much of the audience was wearing 3-D glasses–including Beyoncé pictured here–to properly experience the performance of “Earth Song” and its accompanying film, which was supposed to be part of Jackson’s “This Is It” tour.

Celine Dion, Jennifer Hudson, Smokey Robinson, Carrie Underwood and Usher sang the piece, along with a recording of Jackson.

Special 3-D glasses were also available at Target for home viewers of the music awards show, so if you still have them, use them for this video from the television show–and below it, Colbert with the new Apple (AAPL) device:

Today, the news was the worst possible for Academy Award-winning actress Jennifer Hudson, an impossibly talented and obviously lovely singer and actress, after the body of her seven-year-old nephew was found after an intense search of the Chicago area.

Julian King was murdered, along with Hudson’s mother and brother, in a horrific crime police are trying to solve now. The main suspect in the case is the estranged husband of Jennifer Hudson’s sister and the mother of Julian.

Hudson used her MySpace page to encourage fans to help in the now tragically-ended search for the boy, and news stories broke all day long, fast and furious. Hudson’s mother and brother were found dead several days ago in the family’s home on the city’s South Side.

No surprise, Internet video is popping up all over, many in the form of condolences to Hudson and her sister in the form of songs and music mashups.

The first and second videos are typical, while the third is Hudson herself singing her signature song–”And I Am Telling You”–from the movie, “Dreamgirls.”

Words cannot express the pain of her family’s loss. But her singing, as you will see, expresses so very much.