If you purchased a new laptop recently, especially an Ultrabook, you may have noticed a certain dearth of USB ports. Indeed, my Samsung Series 9 has just two of them. Two! A mouse here and an external hard drive there, and bam, no more ports.

Fortunately, it's a simple matter to add extras. In fact, you can daisy-chain something like 67 million USB ports off of just one, so your expansion options are fairly endless.

And if you've shopped around, you've no doubt seen USB hubs in all shapes, sizes, and prices. How do you know what kind to buy?

There's one important rule of thumb when shopping for any USB hub: make sure it's a powered hub. That'll cost you a bit more, and add the hassles of an extra cord snaking across your desk and an extra device to keep plugged in, but it's worth it.

You see, the USB ports in your PC produce a small amount of power. If you "split" a port (by plugging in a hub), that power likewise gets split between the additional ports. And depending on what kinds of devices you're plugging into the hub, there might not be enough juice for everything.

That's why it's essential to choose a powered hub, one with its own AC adapter. You can occupy every port with power-sucking devices and not have to worry about limited amps leading to operational issues.

I can't tell you which powered hub is best, but one of the most popular options is made by Anker: it's a 7-port USB 3.0 hub that Amazon currently sells for $34.95 shipped. If you've found a hub that's better and/or cheaper, tell me about it in the comments!

Contributing Editor Rick Broida writes about business and consumer technology. Ask for help with your PC hassles at hasslefree@pcworld.com. Sign up to have the Hassle-Free PC newsletter (which is included in the Power Tips newsletter) e-mailed to you each week.