How did Microsoft's Virtual Earth birds eye view imagery get collected?

Question

Did they fly a plane over specific area, or were they all from satellites zoomed way in, or other?

Answer 1

They bought it from aerial survey firms which use planes and satellites.  I don't use VE, but if you use Google Earth, there is an option way, way down at the bottom of Layers (past More) to turn on the border of the photos used to make up the image along with the years taken and the source.  In some cases, only part of one older photo is used to fill in a gap between two newer ones.  And the closest views of a city may be taken from planes while the blurrier views of small towns and rural may be only satellite.