Lingo is a pioneer in the VoIP arena, but more important is its outstanding pricing. For $19.95 a month, you get unlimited calling to the U.S., Canada, and Western Europe (except for Iceland and Greece). And if you call Asia frequently, take heart: Lingo also offers an Unlimited Asia plan for $34.95 a month.

Its online account management page is encouragingly secure—it and Broadvox are the only VoIP services that use a secure Web connection (HTTPS). Despite that, Lingo does have a few shortcomings when compared with its competition. We were less than enthusiastic about the Web interface. Once logged on, you aren't greeted with links to the most commonly used functions, or a useful display of voice mail status or call logs. Instead, you find an overview of your account profile—not so helpful.

Another relatively minor annoyance: Four large menu tabs adorn the top of the page, including Home Plans (which describes various service plans) and How It Works. Clicking on any of them will give you additional information but will also require you to log back on to the service—a less-than-ideal menu design.

Lingo offers all the features found in the other top services, such as call rejection (for blocking anonymous callers), various levels of call forwarding, scheduled call forwarding, do not disturb, and simultaneous ringing. We especially like the ability to upload a WAV file to customize your personal greeting.

On call quality, Lingo's performance was either average or below average on most of our tests. The frame-muting ratio (which indicates dropped frames or missing bits of conversation) was the worst in our roundup (0.8 percent) for a combined ten test runs. Our test jury came to the same conclusion and generally rated the service as sounding a bit tinny or thin.

The differences in sound quality are small overall, however. They certainly shouldn't be a deal-breaker, especially for those who want to take advantage of the great Western Europe or Asia pricing plans.