Here's how to upgrade the disk of a MacBook Pro in 45 minutes while keeping all your data/settings/applications:

1. Uninstall rEFIt and make sure your MBP restarts with the Apple 'default' bootloader
2. Follow the iFixit Guide to replace your disk
3. Put the old disk in a SATA-to-USB case (they are available for $7.89 from Newegg.com)
4. Connect the old disk to your MBP and turn the MBP on. (The MBP automagically recognizes the old system and runs it)
5. Open the Disk Manager and partition your new disk.
6. Select your new 'system' Volume and open the "Restore" tab.
7. Drag your old 'system' Volume to the "Source" field and your new 'system' Volume to the "Target" field. Click on "Restore", the contents of your old disk are now copied to the new disk.
8. After the restore process finishes, shutdown your MBP.
9. Disconnect your old disk and turn on your MBP.
10. Voilà. You are booting from the new disk and all your data/settings/applications are there too!