Other programs with gravity research which take late applications (though won't necessarily have any money left, so email first) ...
Best program that does gravity research (for getting into late) is U. Texas Brownsville. They are so new that they don't even offer the PhD. If you attend UTB you get your PhD sort of through U. Texas San Antonio, if I recall.
From this description they may look like a high grade community college, but actually they have one of the best gravity departments in the US with 9 astronomy / gravitation people:http://www.phys.utb.edu/research/astro.shtml
Because of this combination of low profile / high quality, this is easily
the best place to put an application for late admittance to a gravity department. In fact, people interested in this should apply before the deadline.
Also, I did the research on Brownsville, and it's a relatively low crime area. I bet it has great food. And the warmest winter in the continental US. Plus it's close to the ocean and so doesn't get that hot in summer. But it's relatively low cost housing. An advantage of Texas is that there's no state income tax which simplifies your life.
I got admitted to UTB last year. They were very nice, but I chose Washington State instead partly because it was a shorter move and partly because I fell in love with the campus here from the first visit. But I told UTB that over the years I'd send graduate students their way, so please mention that Carl Brannen suggested applying there. It's the place I'd love to have a postdoc at.