How do you improve on the best all-in-one desktop computer in the world? You add a built-in webcam, an übercool remote, make them faster, and drop the price (at least on the little guy). That’s exactly what Apple has done with it's new iMac G5 20" ($1699). It includes Apple’s award-winning iLife suite, and the new FrontRow interface which allows you to control your movies, music, pictures, and DVDs from across the room via the included remote. Now if only it came in black to match that new iPod…