Old school but I haven't heard this version before... I love how Britney was sandwiched right between Christina and Beyonce. Her part is longer and fits really well. She has nice harmonies too.
oh god, I didn't know this existed but I saw Usher, Justin Timberlake, JC Chasez, Christina Aguilera, Britney Spears, Destiny's Child, Jennifer Lopez, Alicia Keys, Nelly Furtado, Gwen Stefani, and Bono...I wasn't sure about the rest, but I did like this arrangement and the star power in this! ;p