Another note on Hard Disks... I bit the bullet and paid the price premium for a Western Digital Raptor 10,000 rpm SATA drive and it ended up being a great decision. I bought a cheap secondary drive that was slower for my storage drive and use the Raptor for my OS, program files, and frequently accessed files.

something to consider from the review linked above:

Quote:
RAID 0 generally is the best choice if you require high data transfer rates; in fact, it is possible to almost double throughput numbers by deploying a RAID 0 configuration. However, access times do not improve, and sometimes you will even see an increase in access time. Your everyday life with Windows won't be accelerated much by using a RAID 0 array, even if many people tend to believe that!

Available at NewEgg and others.