Here is an interesting use of this api to forward your phone to wherever you are.

I typically use three browsers, home, mobile, and work.

I set each of my browsers default homepage to a simple php script on my server. The server reads the url to determine where i am, sets the Voipo forward, then finally redirects to my real homepage. All in a blink!

To identify where i am, I've added arguments at the end of the url. I also have basic security but removed it to simplify the example.

Example:
Home: fakeurl.com/voipo.php?loc=home
Work: fakeurl.com/voipo.php?loc=work
Mobile: fakeurl.com/voipo.php?loc=mobi

When I leave for work, I just open my mobile browser (which loads my custom page) and my Voipo phone line is forwarded to my cell phone automagically. When I get to work, same thing, open my work browser and the phones are forwarded to my desk phone, When I get home and open the browser there, it disables forwarding.

If I step out for any reason, opening the mobile browser instantly forwards to my cell.