This has gotten alot of notice in the weblog universe. Scientists Develop Atomic-Scale Memory. Using silicon atoms to represent data 1’s and 0’s has provided data density 10^6 times that of a CD-ROM.

The new memory was constructed on a silicon surface that automatically forms furrows within which rows of silicon atoms are aligned and rest like tennis balls in a gutter. By lifting out single silicon atoms with the tip of a scanning tunneling microscope, the Wisconsin team created gaps that represent the 0s of data storage while atoms left in place represent the 1s. Technology Review

Here

‘s some more detail, with pictures. The problem with this memory? It’s really slow, of course! So far…