Landing page layout adjusts several times during loading

[bovine]

The delayed loading of the Google+ and Facebook iframes on the landing page causes the placement of the rest of the page and the background image to visually jump several times.

There is probably some way to eliminate this visual disturbance by properly setting width/height attributes on the relevant containers.

The background image could also be set to an absolute top-left position with only repeat-x (instead of "center", which makes the background be repositioned as the body dimensions are recomputed during reflow).