If you have a cellular data plan for your notebook or netbook computer, you may feel as though you’re paying a lot for very little flexibility. The plans tend to run about $60 a month, and the signal is tied to a specific data modem, whether it’s an internal or a USB-attached modem. Consequently, you can use only one device at a time, unless you take on significant security risks.

Too bad there’s no easy way to share your notebook’s cellular signal with your phone, media player, PDA, camera, or portable gaming system.

Help may be on the way. Novatel Wireless’ MiFi promises to create a “personal cloud of high-speed Internet connectivity.” Essentially, it replaces your internal or USB-attached cellular modem with a small external cellular modem that doubles as a wireless router. It can distribute the data connection to your notebook, your colleague’s notebook, and any other Wi-Fi-compatible device.

The MiFi is small enough to fit in the palm of your hand. It operates for fours hours on a charge, has a standby time of 40 hours, and recharges in 2 1/2 hours. Look for it to be available sometime in the first half of the year.

Here’s the rub. You can theoretically connect as many as five devices at a time, but that number can be configured down to just one device by the carrier. Novatel Wireless doesn’t have any choice here, as the MiFi has to be approved by each carrier. If Verizon or Sprint decides your MiFi will connect with only one device, that’s how it will have to be.

There’s a lot of potential here. Unfortunately, the carriers may be so afraid that potential customers will use it for a free ride, they’ll miss out on the possibility that data sharing could attract even larger numbers of new customers. The airports are full of road warriors who travel with multiple Wi-Fi devices. A fully configured MiFi could encourage more of them to sign up for cellular data plans.