Although I think it's terrific that Google is opening up their API's, we shouldn't forget the recent security problems
I'm not saying this should stop you from going ahead and tinkering with this stuff (I'm sure going to ;-) ... just be careful out there. It seems that it is fairly easy to abuse servers running the SOAP::Lite module, to the point where I heard somebody claim they wrote a script that gave them root access in under two hours. (They also claimed to be somewhat inexpert with Perl, amusingly enough.)
I'd wait before deploying this on a production box.
Anyway, I've gotta get back to this PHP project, see ya around!