I know month old news, but its still interesting.
"Physicists in the US and Germany have reported on a new way to double the storage capacity of magnetic recording devices. The method, which is compatible with standard lithography fabrication techniques, could help overcome the limits of conventional magnetic recording and allow storage densities of 1 terabit (1012) bits per square inch (M Albrecht et al. 2005 J. Appl. Phys. 97 103910). The increase in storage capacity is made possible by combining arrays of magnetic dots with multiple magnetic layers." [Source: physicsweb.org]