I was unfortunate enough that my new Mac had to be replaced - the USB ports developed a fault. Apple replaced it no quibbles, but didn't copy my data onto the new Mac in the store.
I had a Time Machine backup so I didn't think anything of it until I got home and then had to restore from it. This was more complex than I originally thought because my Time Machine backup is on an unsupported volume type the Migration Assistant didn't find it (even with the unsupported volumes system setting turned on).
I rebooted with the OSX disc from the laptop box. Then mounted the Time Machine backup over AFP:
$ mkdir /Volumes/Backup $ mount -t afp afp://<username>:<password>@<ip-address>/<backup-share-name> /Volumes/Backup
Then you have to force the volume to show up in finder:
$ disktool -l .... Loads of output .... $ disktool -m <volume_description>
Then under the 'Utilities' menu of the install disc there is an option 'Restore from Backup...'. Select this then select the visible backup, it gives you a choice of which backups you would like to restore, and then to which hard disk to restore to. Select which ones you want and then click restore, mine took just under two hours.
HURRAH FOR BACKUP!