If you haven’t heard about Monsters vs. Aliens, don’t feel bad. Until today neither had I. That’s about to change, however, as Paramount unveils details around its first computer animated picture produced as a 3-D picture.

The gimmick is that the movie is produced in Ultimate 3-D technology for digital distribution, making this the first computer animated movie produced in 3-D, as opposed to movies like Meet the Robinsons that were adapted for 3-D. According to Dreamworks Animation head Jeffrey Katzenberg, digital projection will result in a perfect image on the screen, ”There is no ghosting, eye strain, or nausea.”

So, gimmick aside, what’s Monsters vs. Aliens about? Well, it’s described as a throwback to the old B-movie days of the ‘50s according to Rope of Silicon. You know the days, where a Martian invasion was just moments away and science produced rubber creations on a weekly basis? The story will center around a California girl who grows to 50-feet after being hit by a meteorite full of space goo. When the U.S. government captures her, she discovers they’ve been capturing a variety of monsters for years.

The movie is getting showcased at ShoWest, leading Paramount and Dreamworks Animation to release some details about the movie beyond the simple plot. For instance, Variety reports the movie will star the vocal talents of Reese Witherspoon (Walk the Line), Hugh Laurie (House), Will Arnett (Arrested Development), Seth Rogen (Knocked Up), Rainn Wilson (The Office), Stephen Colbert (The Colbert Report), Kiefer Sutherland (24), and Paul Rudd (Knocked Up). Witherspoon will play the movie’s protagonist, while other members of the cast will play aliens and monsters along the lines of Dr. Cockroach PhD (Laurie) and a half-ape/half-fish creature (Arnett).

Expect more news and images from the movie to come with ShoWest coverage this week, like the image to the right (see a bigger version in Rope of Silicon’s story), even though the movie isn’t currently planned for release until March 27th next year.