Mariah Carey's "We Belong Together" nets a second week at No. 1 on Billboard's Hot 100, and is again the chart's greatest airplay gainer. The second single from her Island Def Jam album "The Emancipat

Mariah Carey's "We Belong Together" nets a second week at No. 1 on Billboard's Hot 100, and is again the chart's greatest airplay gainer. The second single from her Island Def Jam album "The Emancipation of Mimi" is also No. 1 for a second week on the Hot R&B/Hip-Hop Songs chart.

Refusing to fade away is Gwen Stefani's "Hollaback Girl." The former Hot 100 No. 1 is No. 2 there for a second week and maintains its chart-topping position on the Pop 100, Hot Digital Tracks and Hot Digital Songs charts.

Also sitting tight on the Hot 100 are Ciara's "Oh" featuring Ludacris (No. 3), 50 Cent's "Just a Lil Bit" (No. 4) and the Black Eyed Peas' "Don't Phunk With My Heart" (No. 5). "Just a Lil Bit" is also No. 1 on Billboard's Hot Rap Tracks chart for a fourth consecutive week.

Tracks making gains among the Hot 100's top 10 are led by Kelly Clarkson's "Behind These Hazel Eyes," which climbs 8-6 and is the Hot 100's greatest sales gainer. Will Smith's "Switch" creeps forward 9-8 and the Killers' "Mr. Brightside" makes a 12-10 jump into the top tier. In February, "Brightside" reached No. 3 on Billboard's Modern Rock chart.

Sliding backwards but still among the Hot 100's top 10 are the Game's "Hate It or Love It" featuring 50 Cent (6-7) and Clarkson's "Since U Been Gone" (7-9).

Among the notable moves elsewhere on the Hot 100 this week are the 20-15 surge of Ying Yang Twins' "Wait (The Whisper Song)," a title that has for weeks been No. 1 on Billboard's Hot Ringtones chart. The Pussycat Dolls' "Don't Cha" featuring Busta Rhymes takes a 36-19 jump, while Coldplay's "Speed of Sound" advances 29-21, having previously peaked at No. 8.

"Pimpin' All Over the World" by Ludacris featuring Bobby Valentino is the Hot 100's top debut at No. 81. Also joining the ranks is Faith Hill's "Mississippi Girl" (No. 85), Blake Shelton's "Goodbye Time" (No. 95), Rihanna's "Pon de Replay" (No. 97) and Bobby Pinson's "Don't Ask Me How I Know" (No. 99). Returning to the tally this week is Kem's "I Can't Stop Loving You," which reappears at its previous peak of No. 98.

On Billboard's Hot Country Songs chart, Keith Urban's "Making Memories of Us" is No. 1 for a third straight week, while the list's newest songs include Trace Adkins' "Arlington" (No. 42) and "Bless This Broken Road" by new "American Idol" Carrie Underwood and Rascal Flatts (No. 50).

Green Day's "Holiday" is No. 1 again this week on the Mainstream Rock chart, while Nine Inch Nails' "The Hand That Feeds" is on top of the Modern Rock tally for a third week.

Shakira's "La Tortura" featuring Alejandro Sanz is spending a second week on top of the Hot Latin Songs chart and Clarkson's "Breakaway" leads the Adult Contemporary roundup for a 14th week.