Flip-Flop Nation.

PHOTO (COLOR): Jennifer Aniston in Chicago.

PHOTO (COLOR): Gwen Stefani in West Hollywood.

PHOTO (COLOR): Reese Witherspoon in Beverly Hills.

PHOTO (COLOR): Gwyneth Paltrow in Santa Monica.

PHOTO (COLOR): Eva Longoria in New York City.

PHOTO (COLOR): Paris Hilton in Miami Beach.

PHOTO (COLOR): Nicole Richie in Beverly Hills.

PHOTO (COLOR): Halle Berry in Beverly Hills.

PHOTO (COLOR): Kirsten Dunst in Hollywood.

PHOTO (COLOR): Great Flip-Flops | Havaianas: "Golden Flowers" flip-flops in blue, $20; havaianasus.com

PHOTO (COLOR): La Redoute: Floral flip-flops in orange, $9.99; 800-246-5111; laredoute.com

PHOTO (COLOR): Deborah Evans: White metallic resort sandals, $98; 480-750-1586; shopdeborahevans.com

PHOTO (COLOR): Juicy Couture: "Malibu" sandals in tucker brown, $45; 888-282-6060

PHOTO (COLOR): Sugar: Yellow & white polka-dot flip-flops, $19.95; flipflopstyle.com

PHOTO (COLOR): Havaianas: "Metallics" flip-flops in orchid, $18; havaianasus.com

PHOTO (COLOR): Chanel: Printed canvas sandals, $585; 800-550-0005

PHOTO (COLOR): ToeGoz: Alligator-strap sandals with leather trim, $34.95; flipflopstyle.com

PHOTO (COLOR): American Eagle: Customized flip-flops, $14.50; ae.com

PHOTO (COLOR): Arizona: Metallic textured flip-flops, $15; 877-346-3527; jcp.com

PHOTO (COLOR): Reef: Brown sandals with jewels of the sea, $18; flip-floptrunkshow.com

PHOTO (COLOR): Three Dots: Green rubber flip-flops, $24; 323-782-0139

PHOTO (COLOR): Old Navy: Pink embellished flip-flops, $7.50; 800-653-6289; oldnavy.com