SAN DIEGO — As Justin Guarini hammed his way through the last of his three solo songs at Tuesday's "American Idol" tour opener, a number of the tickled young girls jammed into Cox Arena pointed their cell phones toward the stage.

It was unclear whether they were treating their friends to a quick listen or calling the other Justin (Timberlake, that is) to tell him their hearts have moved on.

Guarini may or may not be the most talented of the 10 "American Idol" finalists (obviously Kelly Clarkson was the country's favorite), but his natural stage presence compared to the others on the tour easily won over Tuesday's crowd.

And isn't that what the "American Idol" tour is really about? You being the judge, filling in for the brash Simon Cowell, determining which of the finalists is best transforming their 15 minutes of TV fame into legitimate pop star status?

On this cross-country journey, there is no Paula Abdul to tell Jim Verraros that his choreography is two steps behind everyone else. There is no Randy Jackson to say, "Nikki, Nikki, Nikki, your rendition of Fleetwood Mac's 'Rhiannon' was off key."

There are only legions of fans dressed like their favorite "Idols," or in some cases, wearing homemade T-shirts rooting on RJ Helton or Tamyra Gray.

Jackson appears only once, in a taped video message introducing the first song of the evening, EJay Day's "Black Cat." From there, the show takes fans through the finalists as they were voted off, with each "Idol" singing a song, offering some generic gratitude and setting up a video montage of the next performer.

Verraros followed Day with "Easy," but appeared anything but as he rose from center stage on a bench dressed in all white. He moved awkwardly around the stage, and at the song's most poignant moment, Verraros asked, 'Where are your lighters?" perhaps forgetting most of the crowd wasn't old enough to smoke.

A.J. Gill greeted the room with, "Hello, San Diego, my birthplace," before breaking into "My Cherie Amour," which included a funkier dance breakdown than the rendition he performed on TV.

With her long dark hair draped over most of her face, Ryan Starr followed with "If You Really Love Me." Christina Christian picked up where Starr left off with the more adventurous "Ain't No Sunshine." She looked like Janet Jackson, but sounded like India.Arie as her rich voice belted out a dozen "I knows" midway through the Michael Jackson classic. After asking the audience to "come dance with me," Christian enticingly shook her booty and spun in a circle.

Smoke filled the stage to welcome RJ Helton, who crooned "Lately" as hundreds of flashing cameras created a strobe effect. And that proved helpful, since the spotlight blacked out a couple of times. (Technical difficulties, including disruptive feedback, plagued much of the show.)

The "American Idol" theme music from the video montages (which grew increasingly annoying as the show progressed) mistakenly continued over Tamyra Gray's opening seconds of "I'm Every Woman," but it was hardly noticeable over the crowd, which sang along to the Whitney Houston hit.

Nikki McKibbin, who was all about sole (at least three inches on her boots) and soul, followed with her saucy version of Janis Joplin's "Piece of My Heart." McKibbin brought a little needed rock and roll into the show, using pyro, shouting out her guitar player after his solo and screaming instead of singing the final note.

"I know you love this next performer, and he's going to do something you have never seen him do," McKibbin said in introducing Guarini, who rose on a center-stage platform playing piano and singing "Get Here." When he twirled off the bench to face the crowd, the arena went nuts, particularly an older man in the front row — Guarini's now famous father.

Clarkson finally took the stage to the tune of Aretha Franklin's "Respect," the song that quite possibly won her the "American Idol" title. While Clarkson was a smidgen weaker than during her TV performance of the classic, she was still a highlight. And the crowd roared for nearly a minute afterward as she humbly smiled before finally flashing the devil horns, heavy metal's version of a wave.

After intermission, the "American Idol" tour took off like it should have begun. The guys, sporting typical boy band attire (spray-painted jeans and all), opened with 'NSYNC's "Pop," and although they didn't quite pull off the choreography, it was still fun and, more importantly, new. Gill, the best dancer of the bunch, proved he would be the perfect replacement for the other A.J. (McLean, that is) should he ever leave his post as the bearded bad boy of the Backstreet Boys.

The girls, dressed in red and black, took over the stage with En Vogue's "Free Your Mind." With easier choreography, they nailed the singing, and looked sexy doing it, particular vixen Starr in a tiny skirt and top.

The rest of the show was similar to the recent "American Idol in Las Vegas" special, complete with both the Motown and disco medleys.

McKibbin and Gray each also did one more song ("Rhiannon" and the spectacular "A House Is Not a Home," respectively), and Guarini and Clarkson sang two more apiece.

The two RCA Records artists — Guarini's signing was announced Wednesday (see " 'American Idol' #2 Justin Guarini Inks Recording Deal") — chose ballads to please their fans, with Guarini handling "For Once in My Life" and Al Green's "I'm Still in Love With You" and Clarkson crooning "Natural Woman" and the "American Idol" single "A Moment Like This."

The latter, although sung well, was nearly overshadowed by cheesy ocean waves appearing on the screens behind Clarkson. Fortunately, her cute-as-a-button Southern charm kept it a tender moment.

Sappy versions of "That's What Friends Are For" and "I'll Be There" capped off the show, with all the finalists trading verses and dance moves. Fireworks erupted as the group took a bow, but not before unofficial leader Guarini sincerely thanked the crowd for making his summer.

"No, thank you, 'American Idol,' " a girl near the front answered.

The tour hits Phoenix on Thursday (see " 'American Idol' Finalists Plan Arena Tour, Compilation Album").

For more sights and stories from concerts around the country, check out MTV News Tour Reports.