Born in the barrios of Puerto Rico, fine-tuned by Jamaican exiles in Panama, reggaetón is the bastard child of reggae and hip-hop—familiar Caribbean rhythms with a rap strut. Originally an East Coast phenomenon, the Latin wave has crashed onto dance floors around the Bay in the last year. On Friday nights devoted fans flock to San Francisco's Glas Kat, where mischievous women in barely-on halter tops mix it up with well-gelled guys swilling rum. The invitation to dance may be polite, but cordiality soon gives way to come-on. Reggaetón is a hip-grinding good time, and if you can't take the heat, better get out of the cocina.

Late Night at Glas Kat
12:17 a.m.

Las mujeres: Very tight jeans, very high heels, very little else.

Los hombres: Homeboys in oversized sports jerseys or chest-baring button-downs.

The look: Black lights, disco balls, an indoor palm tree.

The pour: 10 Cane rum punch in plastic cups.

The sound: Daddy Yankee, Ivy Queen, N.O.R.E.

Sit it out: When the DJ pumps traditional salsa, it's everyone's cue to grab a drink.

Hey Mr. DJ: Women work the stage, vying for the attention of—well, everyone.

One more thing: It's reggae-tone, people, not reggae-tun.

Fridays, 520 Fourth St., S.F., 415-495-6620.

Elsewhere

Bollywood meets reggaetón at Punjabi Espagnol in this multi-culti Tendernob lounge. Varying Saturdays at Element Lounge. 1028 Geary St., S.F., 415-440-1125.

Newbies and laid-back Senegalese regulars share a tiny dance floor. Thursdays only at Little Baobab. 3388 19th St., S.F., 415-643-3558.