Google Voice does not provide an official API interface, but it can actually be done by means of HTTP and XML requests. Most of the APIs currently available on the Web are ultimately traced to Chad Smith's theme post.
To send SMS through Google Voice, first login to Google Voice account, and then take out the page "_rnr_se" parameters, and finally this parameter and the other cell phone number, SMS content post to Google Voice SMS address can. Tyler Hall once wrote a Google Voice PHP class, but I tried it unsuccessfully, always stuck in the process of logging into Google Voice. I've developed this class for two times and rewritten most of the code.
After a practical attempt, instead of using Chad Smith's XML request address, we used the mobile terminal version of Google Voice to request the address and changed the parameters of the post request as needed, and finally got a Google Voice SMS delivery tool based on PHP, Call address in http://www.lostleon.com/tools/googlevoice/, project address in http://phpgooglevoice.googlecode.com/.
Unfortunately, the sky Wing 189th code is not supported by Google Voice. Move the 158th code test pass.