24

24 - Season 4 (Excerpt 1) (QuickTime)
24 - Season 4 (Excerpt 2) (QuickTime)
24 - Season 4 (Excerpt 3) (QuickTime)

Having wrapped its fourth season recently, 24 is probably the most widely seen recent example of split-screen storytelling. Every episode contains several multi-frame scenes. The majority are of people talking on phones or intercoms across great distances. At other times, one of the multiple subframes is used to show the point of view of a character in another subframe.

Be sure to check out this 2002 Salon article on 24 and split screens. It's a good recap of the history of and theories behind split-screen imagemaking.