Kramer,
Excellent and thorough answer. Thanks alot! The voicemail issue is an imperfection but at least the "one number" goal is a possibility. I will have to check and see how Google's system handles voicemail...
I never thoroughly checked out Skype after learning that they had such poor customer service (I could be wrong, but that was my impression). Sounds like you have had a very good experience with them. Have you had any interaction with Skype customer service or have you simply not had a need for this department?
Thanks again. Saver
Hi Saver, I have never had a need to use customer service, thankfully. I doubt you will get much customer service out of any cheap VOIP provider. For instance, I am paying $60 per year for a pretty impressive service from Skype, probably can't expect much service.
On the forwarded calls when you are abroad, the call quality actually seems to be pretty good, better than an ordinary Skype call over WiFi.
Skype also has some local numbers you can buy or use or something like that to call from your cheap local mobile phone to the USA. I don't do that, I make USA phone calls from my netbook or my Ipod Touch over WiFi. This means I can't call the USA when I am away from my apartment. Actually, my pay-as-you-go mobile phone in Colombia allows calls to the USA for about 11 or 15 cents per minute (nothing to do with Skype), I can't remember which, but the call quality is not the greatest.
I didn't add above one more interesting use of the Skype service. When I am in the USA, I use a Skype Phone from Phillips that I bought a couple of years ago. You hook up a little thing to your home router. Then the Skype phone itself can be located anywhere in the house (along with the battery charger), just like a regular home phone that is wireless. When someone calls your Skype In number, the phone rings. Your computer does not have to be on. The quality is better because it is not using WiFi, as there is a base unit attached to the router. Unfortunately, Phillips discontinued this product (I got it for $100). They have designed a newer one, but last I checked it is still not for sale in the USA, even after being available in Europe for something like 9 months. Also, this phone is very convenient to make Skype calls from and all my calls to any USA phone are free.
I think there are a lot of VOIP solutions out there. For my particular situation (which is a bit unusual), I have not found anything better than Skype. For instance, I think if you are running a business from abroad, Skype definitely is not high enough quality. For a Perpetual Traveler like me looking for a thorough but not business-quality solution, it is perfect.