If you let them get this comfy, they may stay

There used to be two options on the marketplace for accommodating overnight guests when an actual bed was out of the question: the sofa, or the dreaded sofa bed within. Surely you remember that thin, lumpy mattress, and the bar that hit right across the middle of your back.

Today, there are many more comfortable ways to tuck in your mother-in-law or 6-foot, 4-inch brother. So comfy, in fact, that they may want to visit more often. (Buyer beware.)

From sleeper sofas with luxury mattresses to stylish leather ottomans that hold a fold-out twin mattress to hip satin bedrolls and heated inflatables, there is something for every size of home and budget.

For starters, the familiar (and feared) old sofa bed has been made over for the new century with improved hardware and high-end bedding.

Sleepers are popular

Retailers say 20 percent of all sofas sold today are sleepers, an upgrade that adds a few hundred dollars to the price. Manufacturers have responded to demand by offering more choices, including styles with firmer inner-spring mattresses and flexible Euro-style wood slats.

December is a big month for sofa-bed sales. "It's a constant purchase around the holidays," says Roger Turnbow, vice president of design for furniture manufacturer Mitchell Gold + Bob Williams. "It's our biggest sales period of the year."

Turnbow says his company is always working to improve its sofa bed. Their products, sold at stores such as Crate & Barrel and Pottery Barn, offer 5 ½-inch-thick inner-spring mattresses with recessed bars. They also have a TV-position headrest that pops up at a 45-degree angle so guests can channel surf late into the night.

Warm and comfy

Aero is the company that revolutionized sleepovers 13 years ago, when its inflatable mattress-in-a-bag premiered on QVC. Since then the company has added to the basic design, which featured a plug-in inflation pump, with pillow-top beds, raised beds and kid-size models (a pet version has been discontinued).

This fall, the company introduced a heated Aero-Bed Premier IntelliWarmth bed so the mattress bed doesn't feel like sleeping on a chilly balloon. "It's like an electric blanket except that you are lying on it," says Lisa Mleczko, spokeswoman for Aero.

For the young and the restless who don't mind things at floor level, Urban Outfitters stocks versatile twin-size quilted bed rolls in purple lotus blossom brocade prints (very "Memoirs of a Geisha") or dramatic tufted velvets. It's a great nomadic look that folds in half and ties up so you can stash it away.

At least one manufacturer says there is a major feature still missing in sofa beds. Bruce Hirschhaut is vice president at Carter Furniture, a contemporary upholstery company whose sleek sofa beds include NASA-inspired memory foam mattresses that adjust to the contour of your body.

"What we need," says Hirschhaut, "is a sofa bed that won't open after three days. It simply locks up, and your guests have to go home."