When I bought my HD at Newegg they had a combo deal which included a usb external enclosure (SATA) for free - otherwise it was around $10 plus $5 shipping. Here's what I did:
I put my brand new drive in the external enclosure, and using the included usb cable, connected to my MBP and it powered up fine. I ran Disk Utility to locate, and 'erase' the new drive, formatting it Mac OSX journaled.
Using Carbon Copy Cloner, I did a complete backup using my Mac HD as the source disk and my new disk as the target. I checked the "delete items that don't exist on source" checkbox, and CCC performed a file-level copy of everything on the source disk. Since I had booted off the source disk (the internal HD) CCC did a file-level copy instead of a block-level copy, but I preferred that anyway, since it actually cleans up some fragmentation as it copies.
When the cloning operation was finished, I re-booted my MBP from the external disk to make sure it worked, and booted up. Once I was sure the cloning was good, I swapped drives. I also made sure to re-name the new drive exactly the same as my original, and this allowed Time Machine to keep on doing its thing without having to start over by thinking it was the same drive it had been backing up all along.
I have begun to move away from TM in favor of incremental bootable backup via CCC. Also, I schedule music backups on another external drive and photo/media backups on yet another drive which are strictly data backups, all via CCC. Each backup is a created "task" which I can schedule, or simply have it execute whenever I plug any of those drives in. CCC knows which physical drive is assigned to which backup "task" so I just plug the drive in, and it gets the right backup.
With a large internal HD (500 gig) I've realized I probably need a second 500gig if I want a backup bootable clone which is constantly updated, but for now I'm getting by with an external 320g for the total backup, and a couple of 250g drives for the other data.
My original 120g HD is in a desk drawer (in case of emergency and in case of any issues where I have to take my laptop in for repair (along with my original 2gig of RAM.)
So, I really like CCC as a total solution. I haven't had to pull my original install DVDs out ever.
Note of caution: If your MBP is still under warranty, you might want to be really careful you don't void your warranty by cracking your case yourself. I decided to not risk that, and after I cloned my new drive, I paid $40 to a third-party Apple certified shop to swap the drives to keep it "legal," since I still have two years left on Applecare. I know you can do it yourself, but know what you're getting into with it so there are no nasty surprises if/and when your 8600GT gpu decides to go out on you and you find out it's not covered because you opened up your machine. Just be careful...
