You can use a combination of sipgate.com and google voice to produce a completely free phone service. http://lifehacker.com/#!5349506/make-fr ... ogle-voice
Sipgate is free for incoming calls. If you sign up for google voice and get the free phone number and then link it to your sipgate number people who call will be routed to your sipgate phone. Outgoing calls are made from google voice w/sipgate, call is initiated from google voice, forwards to your sipgate phone (which considers it an incoming call and is therefore free), you pick up your sipgate phone, and then call is forwared to party you actually want to talk to.
It's a little confusing, but once it's set up it works OK. I had problems with sipgate softphone on windows 7 and downloaded mizuphone light as a replacement software; however, the service remains through sipgate, it's just different software.
I've had a little trouble with this method, but it definitely works. The other sweet thing is that you can set up google's voicemail and have transcriptions of voicemail and text messages sent to your email.
I hope that helps someone.