Upgrading a Laptop Hard Drive is a special case. One needs to work with a laptop and its lack of IDE/SATA channels that would normally be used to mirror a drive. Things are usually easier when you're working with a big desktop, but quite workable with a laptop if you're patient.
Now, I'll outline how I was able to upgrade my hard drive from a 4200RPM unit to a 7200RPM unit, while keeping all my data, OS and programs. My drives were the same size, but the same steps should be usable for upgrading to a larger/bigger drive with one extra step.