Hot Summer Party Nights!

Nothing gets between J.Lo and her dance solo – not even her couture! Lopez kicks off summer in style, dancing with hubby Marc Anthony at Naomi Campbell's 40th birthday bash at the Cannes Film Festival.

She's smokin' – literally! The globetrotting heiress keeps her party torch lit while letting loose at Saint-Tropez's Papagayo Club in July.

Dressed to shine, L.C. returns to her reality TV roots, graciously giving The Hills a farewell toast at the series finale party in Hollywood.

Diddy disproves his rap adage, mo' money, mo' problems, while making it rain – dollar bills! – at Miami's Fontainebleau nightclub in July.

Destination? Margaritaville! Frankel and hubby Jason Hoppy leave their newborn daughter Bryn at home to celebrate the reality star’s "Skinnygirl Margarita" at New York's Montauk Country Club in July.

She's his No. 1 fan: Beyoncé feels Jay-Z's beat, while the rapper tears up the stage at June's Bonnaroo Music and Arts Festival in Manchester, Tenn.

This is one star-studded dance party! Vergara gets jiggy with beau Nick Loeb – just a few feet away from Tatum and Dewan, who show off their Step Up moves at a party for Italy's Ischia Film Festival in July.

Don't get carried away, Eva! As her hubby Tony rocks out on higher ground, Longoria Parker gets a little party pick-me-up from her brother-in-law Terence during their Croatian getaway in July.

Spin this! Sammi lets the music take her away as Pauly D takes over the deejay booth at the Jersey Shore soundtrack release party at Marquee nightclub in July.

Butler reigns supreme over the sound machine at Rockstarz Karaoke Bar in Garden City, Mich., in July, where he belted out '80s tunes with Machine Gun Preacher costar Michelle Monaghan.

Nashville knows how to get down! Pickler puckers up to Crow at this year's CMT afterparty – while David Spade and Kid Rock goof off in the background.