I’m sure there are a large number of ways to take whatever old analog handsets you having sitting around and use them with Google Voice, but most of them require things like setting up your own PBX server. Which could make for a fun weekend project if you’re a major geek, but chances are most people would rather use something a little more straight forward. Enter devices like the Ooma Telo ($199-249), which I’ve recently started using for my office phone.
It’s an absolutely fantastic device and very easy to use. The really nice thing about the Ooma Telo is that it comes with a whole new phone number, so setting it up is as simple as adding that number to your Google Voice account. Ooma also offers some additional nifty features like Instant Second Line, Multi-ring, and Call Blocking for a monthly subscription of $9.99. A 60-day free trial of Ooma Premier is included with the Telo.
Alternatively, if you’re looking for something a little cheaper, you might consider the Obihai Obi110 ($49.99) or the Obi100 ($43.99), both are great solutions for integrating your existing phone handsets into Google Voice. These devices use the actual SIP calling function that was added to Google Talk/Gmail last year.