Do you have SATA on your motherboard?
Also, I highly suggest you get a Maxtor Diamond Max 10 rather than the WD Raptor, the Diamond Max 10s are faster in every day use than the Raptor's. That's if you want to go SATA anyway. Plus the Diamond Max 10 goes up in way larger sizes, all the way up to about 300GBs for the same price as the 74GB Raptor.
The Diamond Max 10 has a 16MB buffer, and NCQ support. Those two things really help launch it above the Raptor in every day use. About the only think the Raptor wins anymore is level loading for games, and then its only by like a second or two.
http://www.newegg.com/Product/Produc...82E16822144358
or this:
http://www.newegg.com/Product/Produc...82E16822144391
The Maxtor is much faster, but that WD has another 50GBs of space for only a dollar more. Up to you, I'd personally get the Maxtor.