The summer season beings in earnest with the return of “Last Comic Standing” (8:30 p.m., NBC) and “So You Think You Can Dance” (7 p.m., Fox).

Both dance and stand-up lend themselves quite naturally to television, particularly the easy brand of distraction that characterizes summer filler fare. “Dancing with the Stars” began as a summer series and went on to become a huge hit. The Fox series puts the emphasis on unknown dancers and choreographers and doesn’t rely on the cringe factor of “Dancing with the Stars.” So we won’t see former jocks who just can’t dance or celebrities grasping for one more moment in the spotlight.

Promotion is at the heart of “Last Comic Standing.” Bill Bellamy (“Def Comedy Jam”) returns as host, and he’ll be joined by a parade of talent scouts who just happen to be TV celebrities. It’s “Audition of the Network Stars.” As such, the judging process is a mixed bag. During the Manhattan tryouts, “Sopranos” star and “Tonight Show” regular Steve Schirripa and “Law & Order: SVU” star Richard Belzer show a real inclination for edgy male comedy and express boredom with the more involved routines of female stand-ups. But in Tempe, Ariz., Kathy Najimy (“King of the Hill”) and Fred Willard (“Back to You”) are pushovers for anything except freaky-costumed comics.

It’s hard not to watch some of these unknowns without some regret. Many seem like the perfect types to become supporting stars in situation comedies and follow in the footsteps of their talent scouts, including Richard Kind (“Spin City”), French Stewart (“3rd Rock”), Dave Foley (“NewsRadio”), and George Wendt and John Ratzenberger of “Cheers” fame. But with the sitcom’s future rather uncertain, you have to wonder where the “Last Comic Standing” will be working.

¢ It’s official: The path to career redemption runs through TV comedy. This season, three scandal-plagued celebrities made guest stints on their way back from trouble. Paris Hilton appeared in a quick scene on “My Name is Earl.” Britney Spears had a cameo on “How I Met Your Mother” and seemed to like it so much that she returned for a second time. And tonight, Lindsay Lohan will appear on the season finale of “Ugly Betty” (7 p.m., ABC). The “Mean Girls” star plays a mean girl from Betty’s high school years who pops up again in Betty’s life. Lohan’s character will return in episodes next season.

¢ “Grey’s Anatomy” (8 p.m., ABC) also wraps up its season tonight with a two-hour episode. Viewers looking for the season finale of “Lost” will have to wait until next Thursday.

Tonight’s other highlights

¢ A convicted shoplifter vanishes on “Without a Trace” (9 p.m., CBS).

¢ Choreographer Tina Landon appears on “Step it Up & Dance” (9 p.m., Bravo).

¢ “Tougher in Alaska” (9 p.m., History) follows a group of men working on electricity lines in Fairbanks during a bitter winter.

¢ Three young people offer first-person accounts of their struggles with mental illness on “True Life: I Have Schizophrenia” (9 p.m., MTV).

¢ The “Cops” parody “Reno 911!” (9:30 p.m., Comedy Central) enters a new eight-episode season.

Cult choice

Gene Wilder stars in the 1971 musical adaptation of “Willy Wonka and the Chocolate Factory” (7 p.m., Family).