All the money spent by the United States space program is not spent looking at the stars. NASA is composed of a vast and varied network of scientists across the academic spectrum involved in research and development programs that have wide application on planet Earth. Several of the leaders in the field of remote sensing and archaeology were recently brought together for a NASA-funded workshop in Biloxi, Mississippi. The workshop was organized specifically to show these archaeologists and cultural resource managers how close we are to being able to "see" under the dirt in order to know where to excavate before ever putting a shovel in the ground. As the book that resulted from this workshop demonstrates, this fantasy is quickly becoming a reality.
In this volume, eleven archaeologists reveal how the broad application of remote sensing, and especially geophysical techniques, is altering the usual conduct of dirt archaeology. Using case studies that both succeeded and failed, they offer a comprehensive guide to remote sensing techniques on archaeological sites throughout North America. Because this new technology is advancing on a daily basis, the book is accompanied by a CD intended for periodic update that provides additional data and illustrations.
She also has a page developed with more links! Plus some other books not dealing specifically with archaeology.
I think part of the problem is that RS has been kind of in the experimental stage with a lot of people using it on and off and with mixed results. Sometimes it's been very successful, such as the radar rivers imaged by the space shuttle (see here, too). [And while looking up those links I also found this one that has more references] Other times, not so much. Probably much of the problem is that it's pretty expensive and the data one gets, especially from satellites, is much too coarse-grained for archaeologists to work with. And it needs to be validated as well. Plus, well, anthropologists aren't generally trained in that sort of thing. But it's coming along.
There's some work being done with ground penetrating radar in Egypt that's tending to be fairly succesful. They can map out mud brick structures under the sand and get a fairly accurate map of what's there. I visited the people working there in 2003 but for the life of me I can't remember who it was. Grrrrr.
Check out NASA as well; they're doing quite a bit on it.