Many travel gadgets are so tricky to master that they never make it out of your bag, but these portable multitaskers are easy—and fun—to use.

1 Clarion N.I.C.E. (Navigation In-Car Entertainment) WHAT IT IS A portable in-car navigation and entertainment center. WHY YOU WANT IT This isn't the first car-nav system with a seven-inch monitor, 3-D maps, and a wireless remote control. But with its plug-and-play portability (it's a bit bigger than a hardcover book), satellite radio and movie-playing capabilities, and 20 GB hard drive—to store GPS data, music, and photos—it's the most multifaceted to date. HIGHLIGHTS It ejects from dashboards and connects to a computer via USB for media transfers or to a stereo to stream tunes; it grasps windshields with a suction-cup mount. LOWLIGHTS Its portability makes it easy to steal—don't leave it behind in your rental car. 800/347-8667;; basic system $1,400, satellite radio receiver $200.

2 Eaton Home Heartbeat Home Awareness System WHAT IT IS An omniscient security setup that watches your house while you're away. WHY YOU WANT IT This system features a base station; wireless sensors to place in your home to detect opened doors and floods; and a key chain with an LCD screen that lets you check in on your property. The Home Heartbeat also sends text messages to your cell phone and an e-mail if a sensor is triggered. HIGHLIGHTS It can cut off your water supply to stop a flood via an electric water valve. LOWLIGHTS Unlike an alarm system, Eaton's setup leaves it up to you to solve any problems that arise. Water valve may require professional installation.; $150 for base station, remote, and door sensors. Available late spring; preorders available now.

3 Olympus m:robe MR-500i WHAT IT IS An MP3 player and digital camera in one, it stores 5,000 songs or 20,000 photos (20 GB worth of information), and takes digital snapshots that can be displayed on its color screen. WHY YOU WANT IT The m:robe forgoes trivial frills like a voice recorder and games, and instead squeezes a 1.2-megapixel digital camera and a 3.7-inch color touch screen into a package that's about the size of a deck of playing cards. HIGHLIGHTS You can add a custom sound track to automated photo slide shows, and send photos via USB directly to a PictBridge-enabled printer. Its eight hours of battery life means it lasts longer than most flights. LOWLIGHTS Mediocre snapshots can't compete with those of digicams. No zoom or flash. Average sound quality. 800/201-7766;; $500.