A new technique for cloaking objects from all kinds of waves is illustrated with animation on http://vimeo.com/5406206. An explation is at Phys.org.

..."We have shown that it is numerically possible to cloak objects of any shape that lie outside the cloaking devices, not just from single-frequency waves, but from actual pulses generated by a multi-frequency source," says Graeme Milton, senior author of the research and a distinguished professor of mathematics at the University of Utah.
"It's a brand new method of cloaking," Milton adds. "It is two-dimensional, but we believe it can be extended easily to three dimensions, meaning real objects could be cloaked. It's called active cloaking, which means it uses devices that actively generate electromagnetic fields rather than being composed of 'metamaterials' [exotic metallic substances] that passively shield objects from passing electromagnetic waves."
Milton says his previous research involved "just cloaking clusters of small particles, but now we are able to cloak larger objects.""...