Good news: Foot doctors say we no longer need to feel guilty about wearing flip-flops.

"They're much better than they used to be," says Austin, Texas, podiatrist Gary Prant. "Some of them have pretty good support." Prant has been dealing with foot problems for 30 years. He remembers when all flip-flops were just floppy little rubber thongs. In those days, podiatrists and orthopedic surgeons uniformly railed against them. But new designs in flip-flops with firm soles and arch supports have led many doctors to flip-flop on the issue.

All flip-flops are not created equal, of course. Doctors favor ones that are less floppy. The American Podiatric Medical Association posts a long list of flip-flops and other sandals it considers acceptable on its website, apma.org. Prant says his favorite flip-flop brands include Naot, Birkenstock, Teva and Terox.

A video on the podiatrist association website warns that flip-flops aren't the right choice of footwear for every occasion. It urges you to avoid them for work, sports or any trek of considerable distance.

The American Podiatric Medical Association offers these tips:

- Flip-flops should bend at the ball of the foot only. You shouldn't be able to bend the entire flip-flop back on itself or twist it.

- The flip-flop should have built-in arch support.

- To keep blisters down, it's best if the shoe's straps and toe post - the part that goes through your toes - are made of soft leather or fabric.

- Your foot should not hang off the edge of the flip-flop.

- Cracked or frayed flip-flops can cause blisters and should be thrown away.

- As a matter of safety, don't wear flip-flops for yard work.