I activated SkypeOut today so I can test and see how well it works. Being that it was too early to call anyone, I will wait and try an international call later tonight and see how it sounds.
The activation was very straightforward. All it took was a credit card. The bill in Euros and they clear in Luxembourg so my guess is USA customers will not only pay a surcharge on the difference in Euros to dollars but also in the credit card fee associated with International coversions.
The other element of making a call is to remember to use the + or 00 when dialing. For someone who travels internationally, it's a no brainer. For those who never do, it may take some getting used to.