At beaches across the country, a few brave men may soon be wearing their underwear in public. Or maybe it will just seem that way. Take a look at the square-cut swimsuit. Inspired by the retro trunks of the 1950s, but in stretchier fabrics, these shorts cling to your body like a pair of boxer briefs. Fashion experts say they're a compromise between the boring board short and the too-skimpy Speedo. "We've lost the two ends of the spectrum," says Simon Southwood, owner of Sauvage Swimwear in San Diego. "It's a little more flattering than either." Ah, for some, perhaps. Just remember: you've got to provide the abs. If you think you're buff enough, "square" choices include the orange and spotted shorts pictured ($48 each; sauvage wear.com ). Other designers offering the style include Hugo Boss, Calvin Klein and Diesel (the blue and green shorts below are available at Saks Fifth Avenue for $50 each). But you'd better hurry. The department store reports a camouflage suit from Michael Kors has already sold out before the summer. Well, what if you are worried about wearing your underwear in public? Relax. Extra lining in the front will prevent anyone from seeing too much of you at the beach.