The Center for X-Ray Optics (CXRO) at Lawrence Berkeley National Laboratory works to advance the science and technology of short-wave optical systems with applications using extreme ultraviolet light (EUV), soft x-ray radiation and nanostructure fabrication.
On their website they offer some nice tools with respect to x-ray interaction with matter.

Like del.icio.us 2collab is a social bookmarking site where you can store and organize your favorite internet resources. It is less visited and arranged than del.icio.us, but quite comfortable if you use services like Science Direct or Scopus.

The Student Research Opportunities Program (SiROP) is a non-profit organization connecting international network of universities and institutions. The purpose of SiROP is to enhance student education and support scientific research by giving motivated students the opportunity to actively collaborate in ongoing research projects both locally and internationally.