Margaret Hoelzer of King Aquatic Club set the world record in the 200m back with a time of 2:06.09, three-tenths ahead of the former mark held by Zimbabwe's Kirsty Coventry.
A little later, Weber-Gale broke the American record in the 50m free in 21.47. Then in the semifinals of the women's 50m free, the American record fell twice, once in the first heat at the hands of Trojan Swim Club's Jessica Hardy (24.48), and then once again in the second heat at the hands of Coral Springs Swim Club's Dara Torres (24.38).
In between those swims, Michael Phelps of Club Wolverine recorded his fifth win of the meet in the men's 100m butterfly in 50.89, while Hoff took her fifth win in the women's 800m freestyle in a meet record time of 8:20.81.
Those swimmers, plus second-place finishers Elizabeth Beisel (200m back), Ian Crocker (100m fly), Kate Ziegler (800m free) and Ben Wildman-Tobriner (50m free), were named to the U.S. Olympic Team in their respective events Saturday.
A number of other swimmers were added to the Olympic Team based on their efforts earlier in the week. Those swimmers included: David Walters of Longhorn Aquatics (4x200m free relay); Erik Vendt of Club Wolverine (4x200m free relay); Kim Vandenberg of Team Bruin (4x200m free relay); Christine Marshall of Aggie Swim Club (4x200m free relay); Wildman-Tobriner of Stanford Swimming (4x100m free relay) and Emily Silver of California Aquatics (4x100m free relay).
Recapping finals, Longhorn Aquatics' Hayley McGregory took an early lead in the women's 200m back and was out about a half second ahead of world-record pace at the 50- and 100m marks.
Hoelzer caught up with McGregory off the second turn and took the lead as she headed into the third length. She was about a half-second ahead of world-record pace at the 150-meter mark and built a body-length lead on the field as she swam for home.
"This is my first world record," Hoelzer said. "It's a wonderful surprise. I'm in awe and amazed. I'm happy to be where I am right now.
"I wanted to be close at the 100 and wanted to go out with Hayley, and be in front of Elizabeth at the end. I don't know how you can't be excited with an event like this."
Beisel, of Bluefish Swim Club touched second in 2:06.92, which was under the former American record of 2:07.16 held by Hoelzer. Beisel also qualified for the Olympic Team earlier in the week in the women's 400m IM.
"It's pretty cool being the rookie," said Beisel, who, at 15, is the youngest member of this year's Olympic Team. "There are so many veterans (on the team) that will hopefully help me out with nerves and stuff."
A familiar scene played out in the men's 100m butterfly, with Ian Crocker jumping out to a half-second lead over Phelps in the first 50, and Phelps using his skills off the turn to propel himself to the front of the pack with Crocker for the race down the homestretch.
Phelps pulled away with about 35 meters to go and cruised to the win. Crocker was second in 51.62.
The two have been the world's fastest swimmers in this event since the 2003 World Championships in Barcelona, where Crocker first set the world record.
"My goal was just to make my third Olympic Team," Crocker said. "I'm relieved to take that deep breath now and go on to Beijing."
Phelps also won the men's 400m IM, 200m free, 200m fly and 200m IM earlier in the week.
"I'm only halfway done," Phelps said. "It's a week of competition that's come to a close, and now we have a month to prepare for the Olympics. Hopefully we can come back in another month and prove the U.S. is the best team in the world."
In the women's 800m free, Hoff and defending world champion Kate Ziegler were stroke-for-stroke for the first half of the race, when Hoff took a slight lead. Hoff steadily built her margin on Ziegler each length after that and touched about four and a half seconds ahead at the finish. Ziegler was second in 8:25.38.
Hoff's meet record bested the 20-year-old mark of 8:23.59 set in 1988 by Olympic legend Janet Evans. In addition to her win in the 800 Saturday, Hoff also won the 400m IM, 400m free, 200m free and 200m IM earlier in the week.
"I've learned that I can handle it," Hoff said of her event schedule. "It's definitely challenging, both mentally and physically, but having done it once now gives me the confidence to do it again."
The men's 50m free marked Weber-Gale's second win of the meet after winning the men's 100m free Thursday, also in American record time.
Weber-Gale faced the top three Americans of all time - Cullen Jones, Ben Wildman-Tobriner and Gary Hall - in Saturday night's finals of the 50. His swim not only made him the fastest American ever, but also the fourth-fastest of all time in this event and the fourth-fastest time in the world this year. Wildman Tobriner finished second in 21.65.
"I knew if I came in here and swam my best times, I'd be in the ballgame to finish in the top two spots,' Weber-Gale said. "It's great to come in here and win both (the 50 and 100 free) and keep my confidence high going into Beijing."
Today's events will be the finals of the women's 50m free and the men's 1500m free. Be sure to catch all the action live on NBC, beginning at 7 p.m. CT.