It's an easy call. Skype is better by far. Both, of course, are VOIP (Voice Over Internet Protocol) telephone service providers. Both allow you to make phone calls from your laptop computer to any landline (or other computer) anywhere in the world.
As many of you know, when I started on this long journey, last October, I signed up for Yahoo Voice. It works just OK. The salient feature is that it's super CHEAP.....one cent a minute. So, I was able to call businesses and friends back in the States. Downside, the connection and sound quality were lousy. One my end, I could hear just fine. But on the other end, folks kept saying, "what did you say? You're breaking up. Are you still there? I can't hear you. Repeat that, etc."
So, here in Merida, 4 months into my trip, I met an American guy from North Carolina. He was using a voice-over-computer service here in the hotel lobby, and apparently having no problems with it all. I asked. He told me, Skype. Now, I had known about Skype, but thought it was a pricey subscription service. Nope. I went to their Web site, and discovered that you can "pay as you go," in other words put in $10 US into your account, and start making calls until you use up that amount.
With both services, I can also call within Mexico. Strangely, that's considered a "long distance" call, and the rate is something like 11 cents a minute. But it's still useful to call onto the next town and check on hotel availability. It's "computer as telephone!"
So, being a reformed academic type, I put them to a test. I did a couple of side-by-side tests, calling a number in the U.S. first on Yahoo Voice, and then calling back with Skype. The call recipient on the other end said Skype was "100% better," and "like being in the next room." The cost is a little more, about two cents per minute anywhere in the U.S. But, in my opinion, well worth the cost to have a clear connection.