I recently discovered a very nice software program that integrates Google Voice with Outlook 2010.  Calling a contact is as easy as right clicking on the contact and clicking “call”.   You can listen to your Google Voice messages, even use the texting feature from within Outlook.  The software is called Clamr!

Here is their website:
http://www.clamr.com/

I had some issues on my desktop getting it installed, but it worked great on my laptop.  The cost is agreeable, but is on subscription at 30.00/year/seat.   The requirements are Outlook 2010 and a Google Voice account.  Works with Exchange or regular pop/imap.   Other nice features are broadcast “texting” to your contacts, file transfers, scheduled conference calls.  I recommend it for increased productivity.