I just used my Mobile phone to get it to call it or you can use this service its free and have Google call that number to do its verifying.
FREE IP Calling with IPKall
If you want to use your Google voice for incoming and out going VOIP calls you can grab a handy little app off the market called GrooveIP it gives you every thing you need to make and take calls with Google Voice, for texting just use the Google Voice app from the market.
Sometimes you have to change the settings in Google Voice to receive calls just go to http://google.com/voice and change your Forward calls to: and make sure the only one checked is Google Chat that way it only rings the Voice account when your Voice number is called.
Hope that helps
