You can use your Google Voice number and receive calls at any computer. The following snip comes from Google's web site for Google Voice:
Make and receive calls in Gmail Google Voice lets you manage all your
phone communications and seamlessly make and receive calls on any of
your existing phones. But what if you don’t have your phone with you?
Or what if you’re in a place with poor cell phone reception, or you’re
travelling internationally and don’t want to incur expensive roaming
charges? Wouldn’t it be great if you could use your computer to make
or receive calls?
Starting today you can use Gmail to receive or place Google Voice
To get started, check the box next to Google Chat in your list of
forwarding phones and the next time someone calls your Google Voice
number, Gmail will notify you of an incoming call. You can take the
call or even listen in as the caller leaves a message, in a single
step right from your computer
There you go, straight from the Google's mouth.