Should I upgrade the HDD in my MacBook?

[N-OS X-tasy!]

[quote chas_m]My understanding from Apple is that although the hard drive in a MacBook is childishly simple to replace, it is not classified as a user-serviceable part -- meaning that if you replace your HD, you void your warranty. Please check with Apple on this, they have not been clear with us lowly reseller types on this.
Note the entry regarding hard drive replacement near the bottom of Apple's D-I-Y part replacement page for MacBooks:

http://www.apple.com/support/macbook/diy/order.html

Pretty clear to me that Apple's stance is that the HD is a D-I-Y part on the MB.