There’s a good reason most new computerscome with four, six, or even eight USB ports: You’re likely to find atleast that many peripherals to plug into them. Here are our picks forthe most useful, amusing, and just plain strange new offerings outthere. — Anne Stuart

-Stay Sharp
True,there’s something ironic about using a costly, cutting-edge piece oftechnology to sharpen a humble wooden tool. But for people who stilluse pencils — such as architects, engineers, artists, andcrossword-puzzle fans — the USB-powered iSharpener could come in handy.A three-inch cube, it will also run on four AA batteries, and niftymulticolored lights flash as you sharpen away. $10. (800) 480-4335, www.x-tremegeek.com

-Just Add Water
Okay,it’s not exactly a traveler necessity, but it is a lot of fun. The USBMini Desktop Aquarium houses two lifelike tropical fish in a tiny(2.5-inch-deep) tank. To see them swim, just add water and plug theaquarium into your USB port. Your computer powers a gentle current anda high-intensity blue light that illuminates the tank in the dark; theaquarium will also run on four AA batteries. $20. (888) 433-5788, www.thinkgeek.com

-Catch a Breeze
Lookingfor an inexpensive, easy way to cool off in your windowless cube, in astuffy conference room, or even on a crowded plane? Try the tiny,collapsible USB Computer Fan. It’s virtually soundless, the flexibleneck puts a gentle breeze right where you need it, and soft plasticblades prevent injury. Built-in blue lights provide gentle illuminationwithout heat, and there are no switches to break. $10. www.curiocityonline.com

-Keep It Clean
Soyou spilled something — maybe wood shavings from your pencil sharpener— all over your laptop. Whisk away the mess with the USB Mini Vacuum.The nifty little device slides between keys to suction out trapped dirtand sports a bristle brush for tidying up vents, the monitor, andanything else. Two settings provide all the power you need; a built-inlight helps you see exactly what you’re cleaning. $9. www.newegg.com