Remember back in the day when free Wi-Fi hot spots filled the streets and a broadband connection was merely an unprotected network away?

Well, somewhat sadly, padlocks and passwords have ended the days of siphoning free internet access off an unsuspecting neighbor. It's progress, I suppose, but it has left us all to fend for ourselves: setting up internet connections at home and work; paying for hot spots at coffeehouses and airports; spending countless hours on trains and in cabs with nothing but a cellular signal to connect us to the outside world.

But no more. A few months ago, a device called a MiFi was introduced to the market. This little piece of innovation, about the size of three or four credit cards stacked atop each other, creates a portable Wi-Fi hot spot wherever you go. It's essentially a wireless router, connecting to a broadband cellular network from many wireless carriers, creating a 30-foot radius of Wi-Fi hot spot, and allowing as many as five secure connections to the network.

The MiFi has a rechargeable battery that can hold a charge for 40 standby hours, or four hours of active use. And it costs about $100 after rebates, plus a monthly subscription charge of between $40 and $60 a month. The pass code is printed on the bottom of the device, so people have to talk to you first if they want to hop on your network.

Now, you may be thinking, "This sounds supercool and all, but why would a small-business owner care about this kind of toy?" First of all, if you're someone who travels frequently for your business, it's a no-brainer. Broadband access wherever you go, for your iPod Touch, laptop, BlackBerry or netbook, is extremely valuable

Previously, if you wanted to have anytime, anywhere access to a broadband connection, you would buy a cellular PC card or USB stick that sticks out of one of the slots in your computer, with a delicately protruding antenna begging to be broken off. These are clumsy solutions, and while it's possible to share the connection with others, it's a technically challenging thing to do. The MiFi is a much more elegant and convenient solution that ultimately costs you the same or less than its predecessors.

But there's another reason to consider this product. Think about how much money you're spending at your office for internet access. Now add the amount you're spending for access at home. Add to that any outside internet services you subscribe to, such as Boingo or Starbucks hot spots. Now compare that to bringing your MiFi to work, using it as your primary internet access device during the day, then slipping it in your bag and bringing it home for the night, or wherever else you're headed. It's possible to cut your monthly internet bill in half.

Watch out, though: There are limits to how much data you can transfer through these devices before you start getting hit with surcharges. Most plans allow 5 gigabytes to data transfer a month for $60. That's about 150,000 e-mails with no attachments. After that, you might get charged a per-megabyte price.

And make sure you really need it! It's hard not to like this little wireless lifesaver. But as powerful as the "gee-whiz" factor is with MiFi, be sure it's something that's either going to help you develop more business (by enabling a remote sales force, for example) or save you money. Otherwise, it's just another in a long line of cool technology products that you don't need.

This story originally appeared on Business on Main