Start looking for the passports and the big suitcases, Shawn Johnson and Nastia Liukin have their trips to the Beijing Olympics all but locked up.

The best Americans showed why they're also the best in the world last night at Philadelphia, all but sealing spots on a team that will be favored to win the gold medal in Beijing. Johnson edged Liukin again, just as she did at the national championships two weeks ago, but the margin is so small, it could be erased with a stuck landing from one or a bobble by the other.

"I remember watching the trials in 2004 and thinking, 'This is the biggest meet of their lives,' " Johnson said. "I don't believe I'm even here. It's crazy. To know I'm so close to securing a spot on the team, pinch me."

Johnson finished with 64 points and Liukin was right behind at 63.5. The finals are tonight, with the top two earning spots on the Beijing squad. But, barring injury, there's little doubt of who that will be, so the intrigue turns to who will get the remaining four spots.

The rest of the team, along with three alternates, will be chosen after a July 20 selection camp at the Karolyi ranch.

Comeback kid Chellsie Memmel had another strong night. Memmel became only the third U.S. woman to win the world all-around title in 2005 (Johnson has since joined the exclusive club) but she was all but forgotten after a blown-out shoulder cost her most of the past two years.

Not anymore. In a repeat of nationals, Memmel finished behind Johnson and Liukin and had the second-highest uneven bar score.

"I hope I've been proving to (national team coordinator Martha Karolyi) that I'm a solid competitor and can be an asset to the team," Memmel said. "I'm very excited with how this week is going and with how championships went. I'm getting more confident with each competition."

Samantha Peszek, a member of last year's world team, was fourth with another strong effort. She's not the most dynamic gymnast, but she's consistent and that counts when Olympic medals are on the line.

Johnson was forced out of her gym for two days last week when the floods that ravaged Iowa left a foot of water in her building. That may not sound like a big deal, but any change in routine is a disruption, especially that close to the trials. And for the two days that she trained at Iowa State, Johnson was working on equipment made by a different manufacturer than she's used to.

But if it was a distraction, Johnson didn't show it. She posted the highest scores of the night on vault, balance beam and floor exercise.

"I tried really hard not to let it affect me. I said, 'OK, this is what I've been given and what I have to deal with,' " Johnson said. "I think it made me stronger mentally and physically. I had to learn to adapt to everything coming on. I was just ready for everything."

DIVING

WILKINSON, DUMAIS IN GOOD SHAPE AT TRIALS

With a string of perfect 10s, Laura Wilkinson and Troy Dumais appear to be Beijing-bound.

Wilkinson, who won gold on the 10-meter platform at the 2000 Olympics, showed she's still the boss of the tower at the U.S. Olympic trials, holding off a challenger half her age in the semifinals last night at Indianapolis.

The 30-year-old Texan received at least one 10 on three of her five dives and finished with 813.20 points. She had a comfortable advantage over 15-year-old Haley Ishimatsu, who finished with four 10s and the highest-scoring dive of the night but was still only second at 757.55.

Wilkinson can lock up her third trip to the Olympics in the finals tomorrow.

"I felt a lot more confident," she said. "I knew what (Ishimatsu) was doing, but I was kind of oblivious at the same time."

Dumais, declaring he will settle for nothing less than gold in Beijing, was just as good in the semifinals of 3-meter springboard. The two-time Olympian received 10s on three of his six dives to build a commanding lead with 1038.30. Chris Colwill was second at 961.00.

The springboard finals are today.

Dumais, a 28-year-old native of Ventura, Calif., finished sixth on springboard at the past two Olympics.