CBS takes time out from its ratings-dominating schedule to broadcast March Madness, the NCAA Basketball Tournament (6 p.m.). Some years back, when CBS lacked for viewers, this was a highlight of its schedule. Now you have to wonder how many people they will be losing by not airing “CSI.”

• “The Tonight Show with Jay Leno” (10:35 p.m., NBC) scores a first of sorts when President Barack Obama becomes the first president to appear on a late-night talk show while in office.

I’m not sure who is taking the bigger gamble here. The president will probably be criticized for lowering the dignity of his office for appearing in a talk/comedy format. If he comes off as too casual at a time of economic crisis, he risks being seen as unserious. But he doesn’t want to bomb, either.

At the same time, Leno also risks being compromised. From the time of Johnny Carson onward, viewers have looked to late-night hosts to roast the chief executive from time to time. Will Leno be less likely to make jokes at Obama’s expense now that he’s been on the couch?

It’s interesting to note that of all of the talk-show hosts, Leno has the reputation for being a fairly friendly place for Republicans. Arnold Schwarzenegger launched his bid for California governor on Jay’s couch, and former “Law & Order” star Fred Thompson also announced his presidential candidacy on “The Tonight Show.”

• Tough times call for creative financing. The provocatively titled documentary “100 Men Own My Breasts” (8 p.m., BBC America) follows women who want reconstructive surgery but can’t afford it. Now there’s a Web site that helps them find groups of people who will help pay their medical expenses. The Web sites make money, and the women get their implants, but just what do the investors receive? The answers range from the altruistic to the creepy. An odd look at how technology and capitalism combine to change the notion of “private property.”

• The Sundance Channel observes the sixth anniversary of the invasion of Iraq with a series of documentaries about the war and how life has changed for both Iraqis and Americans. “Heavy Metal in Baghdad” (9 p.m., Sundance) follows the members of Acrassicauda, a group of rockers who learned English from American movies and from bootlegged CDs of Metallica and Slayer. Their fish-out-of-water status grew more precarious as the sectarian fighting of 2006 heated up. Other related films include “Hometown Baghdad” (10:30 p.m.) and “No End in Sight” (12:15 a.m.).

Tonight’s other highlights

• Earl makes amends to a local eccentric (Betty White) he once offended on “My Name is Earl” (7 p.m., NBC). “Earl” star Jaime Pressly also appears on “Late Night with Jimmy Fallon.”

• A secret high school sorority may be linked to murder on “Bones” (7 p.m., Fox)

• Marc and Amanda offer a few beauty pointers on “Ugly Betty” (7 p.m., ABC).

• Scientists in New York City, Scotland and Belfast try to harness the power of ocean waves to generate electricity on “Man-Made: Aqua Power” (7 p.m., National Geographic).

• Michael’s celebration draws the attention of a new vice president (Idris Elba) on “The Office” (8 p.m., NBC).

• Baseball teams meet in second-round play of the World Classic (8 p.m., ESPN).