Round 1: Price

On the surface, it looks like Skype wins this one handily. After all, Skype is often touted as a free Internet phone service. The truth is that it's free only for Skype-to-Skype calls. That is, both of the call participants need to be using Skype for it to be a truly free phone call. Skype charges users a per-minute fee to call non-Skype users (the service is called SkypeOut), on average between 2 and 3 cents per minute to most parts of the globe. Vonage is actually one of the more expensive VoIP services--the Premium Unlimited plan will run you $24.99 per month for a residential line and includes unlimited calls to anywhere in the United States, Canada, and Puerto Rico. The per-minute fee for international calls ranges from 4 cents per minute (London) to $3.50 per minute (Tuvalu).

Also, Vonage includes certain features, such as voicemail, for free, while Skype charges for those extras. Additionally, in order for non-Skype users to call you via your Skype account, you'll have to pay for a traditional number, a service called SkypeIn.

So, the upshot is this: If your friends and family are scattered around the globe, you'll do well to use Skype, as its international rates are a bargain compared to Vonage's. But if you make lots of phone calls within the United States, Canada, and Puerto Rico, you're probably better off with a service like Vonage, which will let you make unlimited calls within those areas and doesn't require you to ask your friends to join Skype.

The winner of this round? We'll give Skype the edge here, as it's not that hard to convince your friends to sign up for a free service.

Winner: Skype