What's the deal with upgrading your own hard drive? (MB)

[PardonTheWait]

Am I allowed? With RAM, I know they don't mind if you do it yourself, and it won't void your warranty unless you actually damage something while performing the upgrade. Is it the same with hard drives? I'd quite like a 7200rpm drive in my Macbook, but if it'll stuff my warranty I won't bother. I can't find anything on the Apple site about it, I was just wondering if anyone knew for certain on here.

Ta

 

[PardonTheWait]

Swish, ta

(I suppose I should have looked in there actually, but I assumed it wouldn't have been in there for some reason)

 

[PardonTheWait]

I read that the 7200rpm HD was the momentus series.

Groovy, that was one of the ones I was looking at

I might have to do it next payday