The USGS will give you their entire data set (mostly 1/3 arcsecond) if you send them a 500 gb external drive. We expose a web service to get at this data set quickly for our planning flash app and some of our background tasks.
But nothing on an international level?
We are getting international data through their web service currently, but will be integrating an international data set soon.
This is part of the gps stream from most gps devices.