VOIP

Have any of you used VOIP (Voice-over internet protocol) -- like Skype? It is supposed to be really good and cheaper than regular phone service. But I wonder if it works as good. Also since VOIP is the new thing, I'm not sure how it works being away from home, or if you have to be connected to the internet/computer at home. I tried Skype last year but that was when it was just starting and VOIP hadn't really taken off yet. Anyway, I'd be interested in knowing if you've used VOIP and what your experience has been.