I note both call participants must be registered and "active" users (i.e. at least every 14 days), which is not a restriction applying to SkypeOut or SkypeIn. I'm not too keen on the "use it or loose it" approach personally, but I can see how the service would be attractive to certain like-minded users. But being naturally suspicious, I'm also wary of this little gem:

I called from my landline to another registered landline, but still got charged. Why? There are several possible reasons. Please fill out and send us this form and we'll send you an explanation based on your circumstances.

A tad too vague for my liking... you either know what it costs up-front, or don't make the call.

Still, competition for Skype is good. This is a space to watch.

Instead of Skype, have you tried something like Jajah too (yet)?