IGN. This figure is up by nearly three million units since last April, when the global total rung up at 67.2 million.
Conceptualizing that many Xboxes is kind of hard to do, so let's put that figure into a ridiculous, arbitrary context. An olympic-sized swimming pool, for instance, holds about 424,935 Xboxes, assuming a pool volume of 88,528 cubic feet and Non-S model 360s. In order to hold all the Xboxes sold in the world so far, it would require 165 olympic-sized swimming pools, with that 165th pool having a tiny little bit of space left over for some controllers and a copy of Condemned: Criminal Origins.
To put it another way, if every Xbox sold in the world were put on one side of a giant scale, 2,156 blue whales would need to be placed on the other side for it to balance properly, assuming a median weight of 250,000 pounds per whale. That's kind of a lot of Xboxes, you guys.