Seagate's new hard drives combine 4GB SSD's with standard platter based hard drives. The result and benefit of this is, much lower cost, with similar performance to a standard SSD. I was skeptical at first, but check out the video below and you will see why i am ordering some of these. If you want to buy them they are available at amazon for $99.99(250GB), $125.99(320GB), and $134.99(500GB).
Amazon