Beyond TV: Katy Perry, 'Fact Checkers Unit'

NEW WEB COMEDY SERIES "FCU: Fact Checkers Unit" features guest stars like Luke Perry, Jon Heder, Pauley Perrette and Zach Gilford. Launched this week with three episodes, it's based on a short film about overzealous workers at a celebrity mag. Fun site at factcheckersunit.com.

KATY PERRY LIVE ONLINE After the Grammy nominee tapes Tuesday's David Letterman show, she'll do a "Live on Letterman" Web concert from the Ed Sullivan Theater (about 8 p.m.). Watch at cbs.com/lateshow.

'FRINGE' FOR APP DEVELOPERS Fox is sponsoring a contest to create a new app for its drama "Fringe," with cash prizes. Called Pimp My App!, the contest provides developers with criteria and "Fringe" assets upon registration. Details at appnationconference.com.

N.J. 'HOUSEWIVES' OFF-BROADWAY "My Big Gay Italian Wedding" welcomes Teresa Giudice, Ashley Holmes, Jacqueline Laurita, Caroline Manzo and Lauren Manzo to its Manhattan stage for benefit performances Sept. 1-4. The show, whose producers include "The Real Housewives of New Jersey" cast member Dina Manzo, is raising money for Marriage Equality New York. Info at biggayitalianwedding.com.