The 2006 Austin City Limits Festival was once again held at Zilker Park in Austin for its fifth year, and it proved to be yet another successful year for the three-day event as more than 50,000 people filled the park each day, according to the ACL e-mail newsletter. The first obvious change for the festival was planting grass in Zilker park to eliminate the dust-bowl incident of last year, when the wind made the park look like a Sahara sandstorm.

Another improvement was the weather. Last year, temperatures got up to 108 degrees with little clouds or wind. This year, while it was still hot and muggy, at least there was cloud cover, wind and even a little rain to help. There were also more water stations added to keep fans hydrated.

On Friday, the first big act to play was Gnarls Barkley, who played at the headlining AT&T stage at 4:30 p.m. In typical Gnarls fashion, the entire band took the stage as scientists, while “She Blinded Me With Science” played as they came out.

Gnarls went through virtually the band’s entire debut record, including the song of the summer “Crazy.”

Friday night saw a division in the audience as the older crowd went to see Van Morrison, while the younger crowd made their way to see John Mayer.

Mayer put on an impressive set that was heavily made of new material off his new album “Continuum.” Mayer showed he had traded in his soft acoustic “Your Body is a Wonderland” style for several Stratocasters and longer hair. His new electric-blues material meshed nicely with his older material as Mayer broke into slightly revamped versions of past hits such as “Why Georgia?” and “My Stupid Mouth.”

Saturday, the New Orleans-bred jam band Galactic got the crowd dancing at the AMD stage. They jammed their way through several wordless songs with extended guitar, keyboard and saxophone solos, including stunning instrumental covers of Led Zeppelin’s “Immigrant Song” and Jimi Hendrix’s “Manic Depression.”

The Shins were another big act to see as they took the AT&T stage. They played their two “Garden State” soundtrack hits “Caring is Creepy” and “New Slang” and also broke out some new material that will be on their new record, which should come out in the next few months, said keyboardist Marty Crandall.

The Raconteurs were the focus of the AT&T stage Saturday as they ripped through their set.

The band furiously beat out nine tracks off their debut album including the hits “Steady, As She Goes” and “Intimate Secretary”, as well as playing a strangely loud, raunchy version of Nancy Sinatra’s “Bang Bang (My Baby Shot Me Down).”

One of the better performances of the festival this year was the set played by southern rockers Kings of Leon. The band started out with a new song called “Snake Charmer” that had the crowd jumping and screaming. The rest of their set drew from their latest record, the brilliant “Aha Shake Heartbreak” as they blew through “King of the Rodeo,” “Taper Jean Girl” and the perfect set-ending “Slow Night, So Long.” Singer Jared Folowill seemed irritated that the band was limited to a short 45-minute set due to Willie Nelson’s headlining set.

“Sorry we’re playing through these songs so fast,” Folowill told the crowd. “They’re trying to kick us off up here.”

Once Nelson started his opening song, “Whiskey River,” it signaled it was time to chill out and enjoy the rest of the cool Saturday evening.

The final day of the festival had a triple header on the AT&T stage as the final three acts set to play were Matisyahu, The Flaming Lips and Tom Petty & The Heartbreakers.

Matisyahu’s set started at 4:30 p.m. and got the crowd jumping and dancing along to his own twist on reggae and funk. The Flaming Lips took control of the stage as singer Wayne Coyne jumped into the crowd incased in a giant plastic bubble. The Lips’ set was truly a celebration of music as Coyne shot confetti into the crowd and half the stage was taken up by dancing aliens, while the other half was taken up with dancing Santa Clauses.

The band opened with “Race for the Prize,” then energetically rocked through more current songs such as “The Yeah Yeah Yeah Song” and “Free Radicals” off their newest release, “At War with the Mystics.”

The Lips left the crowd satisfied and ready for the evening’s main event, Tom Petty and The Heartbreakers.

Petty took the stage at 8:30 p.m. and stuck mostly to a greatest-hits set list consisting of such songs as “Learning To Fly,” “Mary Jane’s Last Dance” and “I Won’t Back Down.” The band had to leave the stage due to a sudden rainstorm. After about a 20-minute rain delay, the band came back and finished the rest of their fantastic sing-a-long set.

ACL never seems to disappoint and it has become one of Texans’ favorite festivals. With an atmosphere and a lineup like this year’s, there’s no questioning its success.