A Ray of Light

For do-it-yourself enthusiasts, the laser level, which uses a beam of light to tell you when something's exactly horizontal or vertical, is the season's hottest new gadget for the toolbox. These high-tech levels are useful for hanging pictures, putting up shelves or hanging wallpaper without having to mark up your walls with pencil lines, which are necessary with old-fashioned manual levels. But beware: some models stick to the wall with tape or pins that leave holes or marks that are just as annoying to cover up as pencil. Look for levels that mount with a suction cup, like the Ryobi AIRgrip Laser Level ($40), above.