Mom, Can Sam Sleep Over?

At most sleepovers, the demand for beds outstrips supply. That's why furniture makers keep coming up with ways to build in extra sleep space.

Many of the designs are disguised to look, and in some cases act, like something else: a chest of drawers, a chair or mini-sofa, even a wooden sailboat.

At the low end is Playhut's $20 Twist & Fold sleeping bag (available at Wal-Mart), built with a slender steel loop inside that allows it to be folded flat and compact instead of rolled into a bulky mass. Playhut also makes an inflatable mattress that folds up as a princess- or Spider-Man-themed chair and comes with a foot pump. It's $30 at Toys R Us and Wal-Mart.

Flexa, a Danish company, makes a steel-frame chair whose seat quickly unfolds to a mattress. It can be ordered through Baby-2-Teen for $249.

P.J. Kids makes a foam sofa--just right for three- to five-year-olds--that pulls open in a jiffy. It's available in everything from pastel chenille to denim, for $179 to $189, at the Bedroom Factory in Laurel (301-490-1100).

The Fu-Chest looks like a chest of drawers. But unhook two clasps and it opens to reveal a twin or full futon resting in a floor-level frame. The price ($425 or $485; order through 125 West; 888-921-9378; fu-chest.125west.com) does not include the futon, but that can be ordered at the same time ($139 or $169).

Name-brand manufacturers are making youth beds at heights for a trundle or pop-up bed to slide underneath. Stanley's Young America line includes an Under-Bed Storage Bed that slips under a regular bed frame: just pull it out and it springs to regular height. It's $149, plus mattress, at Gladhill Furniture in Middletown (301-371-6800; gladhillfurniture.com).

Lea Industries' lovely line of sleigh beds come with unobtrusive trundles ($399 to $1,200 at Kids Habitat Co.).

Coolest of all is P.J. Kids' limited-edition wooden sailboat ($1,999 at the Bedroom Factory Outlet and Bedrooms Unlimited, Crofton; 301-858-1490). It's big enough to hold a twin mattress on top. With a mast and sail and loads of storage, it serves as a bed, dresser, and toy all in one.