One of the benefits, to me – now living back in the US, is Google Voice. US numbers only, I can call from my cell phone or landline and get low international rates:
If I’m international, I can call my Skype using my Skype to Go number, then dial my Google Voice for 2 cents/minute and make international calls also for as low as 2 cents/minute. So calling London might now cost 4 cents/min versus 20-40 cents/min.
I haven’t tried this yet and I’m guessing the VoIP quality is not great, but in theory, it works!
Google Voice also announces the cost of the call before it makes it, sweet!