My usual source for hard drives is Dabs, since they carry a dazzling array of drives, always have it in stock and they get the finger out and ship on time. I also love their site's interface for drilling down through the various specifications: choose SATA, choose laptop, choose 160-300GB.
300GB? Yes, 300GB. That's not a typo.
I hadn't caught the news that laptop drives had reached this kind of size. I knew Apple had a 250GB CTO option on the latest MacBook Pros, but I didn't know 300GB even existed. The device in question is Fujitsu's MHX2300BT. It's a 2.5" 300GB drive with a 4200rpm spindle and an 8MB buffer. I paid £116 at Dabs for it, which is a pretty nice price.
In between bulging Aperture and iTunes libraries, the chunky iLife '08 install, a Leopard partition and maybe Boot Camp in the future, 300GB is the kind of size one wants in a laptop these days.