You will have to be on the 1.4.1 pre-release or later for this feature. Just so you know, the official 1.5 version will be released September 22, 2006 and will obviously have this as well if you want to wait. But it definitely will not cause you any problems if you load the 1.4.1 release now.
P.S. On the screenshot you embedded how did you create that tear effect?