Seagate's Giant 750GB Hard Drive Expands Universe of Drive Capacity - Yahoo! News: "Perpendicular recording--a shift from the longitudinal magnetic recording process used for the past 50 years--increases areal density by changing the way data is recorded to the drive. 'Everything changes, from the type of media to the type of head,' says Clark. 'At the drive level, you space your bits farther apart because they're standing on end vertically into the media, which makes them more stable and closer together as compared to longitudinal. So now you have more data bits which will slide underneath the heads as [each] head reads and writes.' "