Lo-and-behold, the macbook drive is slimmer. Also, no warranty on it, but I did get Apple to agree to send me a brand spanking new battery. He gave me one of those silicone keyboard covers and a zippered case for free. The only downside is that the drive is only 80gb. TCP, the Apple drives have apple firmware installed on them to make them 100% boot compatible. Most drives are compatible, but may or may not work with all boot disks/burning options.
I can vouch for this. I've done swaps with the UJ series drives before, and had a "PC" one refuse to boot off CDs but would mount them fine once booted into OS X.
How much slimmer is it? Think it'd be possible with a bit of Dremel action?