For a seventh week, Katy Perry's "I Kissed a Girl" is No. 1 on the Billboard Hot 100. Challenges loom from Chris Brown's "Forever," which inches up 3-2, and Rihanna's "Disturbia," which climbs 4-3 after selling a week-best 140,000 digital downloads, according to Nielsen SoundScan.

Another Rihanna song, "Take a Bow," drops 2-4, with Coldplay's "Viva La Vida" and Lil Wayne's "A Milli" holding at Nos. 5 and 6, respectively. Kardinal Offishall's "Dangerous" featuring Akon moves up a slot for the third straight week and is now No. 7.

The Jonas Brothers score the top debut on the Hot 100 for the third time in six weeks with "Tonight," which opens at No. 8. The song sold 131,000 downloads in its maiden week, making the act the first to debut in the top 10 twice in the same year since Madonna in 1998.

The Pussycat Dolls' "When I Grow Up" rises 12-9, and Ne-Yo's "Closer" enjoys a 14-10 gain, a new peak for the song in its 16th week. Also reaching a new high is M.I.A.'s "Paper Planes," which soars 36-16 after selling 102,000 downloads. The song is featured in the trailer to the new stoner comedy "Pineapple Express."

Elsewhere, T-Pain's "Can't Believe It" featuring Lil Wayne opens at No. 29, while Kid Rock's "All Summer Long" jumps 38-34 as the top airplay gainer.
 

On Hot R&B/Hip-Hop Songs, Keyshia Cole's "Heaven Sent" shows no signs of budging from the top after nine weeks. Sugarland assumes control of Hot Country Songs with "All I Want To Do," the third No. 1 of its career. The group's new album, "Love on the Inside," debuted yesterday (Aug. 6) at No. 1 on The Billboard 200.

Foo Fighters start a third week atop the Modern Rock chart with "Let It Die." Disturbed's "Inside the Fire" is in charge on the Mainstream Rock roundup for a 14th week.