No doubt about it: "Low," the debut single by Florida rapper Flo Rida, is irresistible, kinda annoying, and exactly where ringtone hip-hop rests in 2008. More than any other song that's come out this year, the T-Pain-assisted hit (10 weeks at No. 1!) sounds like the future of hip-hop, for better or worse. The rest of Mail on Sunday slams one generic beat against another, hoping for one more score. But producers Will.I.Am and Timbaland (recycling Flo's "Elevator"'s hook in Madonna's "4 Minutes") come up empty. It doesn't help that Flo's flow recalls about a half-dozen other rhymers', none of them particularly memorable.