Vonage V-Phone: use your laptop to make calls via the Internet.

For millions of business travelers, a cell phone or a cell-capable PDA is the communication tool of choice. But for those mobile professionals who insist on lugging their wireless laptops around, the Vonage V-Phone is an inexpensive alternative.

We tested the Vonage V-Phone ($39.99; www.vonage.com), a small flash drive device that plugs into any computer's USB port and lets you make phone calls through a high-speed Internet connection. You start your Vonage service by choosing a calling plan (starting at $14.99 for a residential basic package, up to $49.99 for a Small Business Unlimited Premium plan). Once you sign up, your number, calling plan, and features travel with you wherever you go.

The installation is a breeze. The V-Phone setup features plug-and-play at its best (unless your computer is protected by a firewall, then a more extensive setup process will be required). Just plug the device into your computer's USB port, and the built-in software begins to load immediately. At the end of the installation process, a keypad appears on your desktop and you're ready to make and receive calls.

The Vonage V-Phone includes 250MB of memory that can be used to store files, MP3 songs, digital photos, or anything else you want to take with you. Overall, the Vonage V-Phone worked well enough for what it's designed to do. It's a great solution for laptop users on the go. Just don't expect it to replace your cell phone.