Three marathons, one telethon, and still it seems like nothingthon.
* "Jerry Lewis Muscular Dystrophy Telethon" (continues 6 a.m.-6:30 p.m., Channel 2) -- Jerry Lewis, still at the helm of the TV fund-raising phenomenon he turned into an annual event and media institution, is planning to go the distance again, with help during this 29th annual telecast from Tony Bennett, Boyz II Men, Elayne Boosler, Larry King and others.
* "Don't Tell Mom the Babysitter's Dead" (8-10 p.m., Channel 45) -- This 1991 telemovie, starring Christina Applegate of "Married . . . With Children," is echoed, in a way, in another Fox series, the family drama "Party of Five," which premieres a week from tonight. In that case, though, it's an inverted, more permanent arrangement -- closer to "Don't Tell the Babysitter Mom's Dead." Fox.
* " 'Home Again' marathon" (7 a.m.-8 p.m., A&E) -- In a marathon, what comes after 13 episodes of "Home Again"? Thirteen more episodes of "Home Again," naturally.
* " 'Evening Shade' marathon" (noon-8 p.m., FAM) -- Sixteen episodes of Linda Bloodworth-Thomason's "Evening Shade" sitcom are presented today, but have direct competition on Lifetime, which is presenting . . .
* " 'Designing Women' marathon" (noon-8 p.m., LIF) -- . . . Sixteen episodes of another Bloodworth-Thomason sitcom. Who says cable doesn't provide a dizzying variety of viewing options?
* "Talk Soup" (9-9:30 p.m., E!) -- I make lots of bad jokes, but this isn't one of them: Brian "Kato" Kaelin really is the guest host of "Talk Soup" this week.
* "Law & Order" (11 p.m.-midnight, A&E) -- Another off-network show joins the A&E lineup in reruns -- and this one is a good catch, in retrospect, because each year of the series brings with it a few new cast members. In the opener: George Dzundza and Michael Moriarty, both of whom have since left the show.