The wizards at Hitachi have announced a 400GB 7200RPM SATA hard drive. This C|Net article explains why you want one.
I want four, attached to a SATA RAID-5 card. That'll give me 1.2TB of redundant storage, allowing me to capture an entire year's worth of NASCAR Nextel Cup races as well as the other televised flotsam and jetsam that randomly attracts my attention. (oooh, shiny! :-)
Back in the day, people spoke of terabyte databases as if they were glowing, golden room-sized blobs of unobtainium. Now, any geek with less than $2k can put 1.2TB (1.6TB if you don't care about redundancy) into a full-tower PC.