Vandenberg Air Force Base, in California. The first Falcon 9 v1.1 launch, for CASSIOPE, was from Vandenberg.
Here is a sign that SpaceX has at Vandenberg, implying that they intend to both launch from and land at Vandenberg: http://i.imgur.com/YW4tmkR.jpg
Vandenberg is really only useful for polar orbits, and perhaps retrograde orbits, due to it's high inclination and it's geographical relationship to the ocean.
Similarly, launches from the east coast will land back at the east coast. It will look something like this: http://i.imgur.com/NEi7qKp.jpg (related discussion: http://www.reddit.com/r/spacex/comments/23l96t/spacex_falcon... source: http://www.spacelaunchreport.com/falcon9v1-1.html)
The engineering of the Saturn V just continues to amaze me!
"The engine shutdown was determined to be caused by severe pogo oscillations measured at a strength of 68 g and a frequency of 16 hertz, flexing the thrust frame by 3 inches (76 mm)."
It was this close to ripping the whole rocket apart, but it managed to withstand some incredible shaking until the engine shut down.
One of my friends in Houston was dealing with pogo in rockets specifically. So yes, I am familiar with pogo in general, and I had heard of it during the Apollo program.
Yes, that's true now, but at the height of the Shuttle program, Vandenberg AFB had begun to build, and planned to use, a Shuttle launch facility. So that's a policy change, because there was a time when they were more than willing to launch something very heavy over land to their east.
[1] http://www.spacearchive.info/vafbview.htm "With the exception of the Pegasus XL, all Vandenberg AFB launches take place from the base. Minuteman III missiles climb rather steeply and head due west. Delta, Taurus, and other satellite launch vehicles fly towards the south and climb more slowly."