External hard disk

If you have a Firewire port in your computer, then it is better to go for an external hard disk with a Firewire interface. Otherwise, a USB external hard disk will do the job.

Below are some links which might help you take a decision:
Link 1: http://www.techsaver.com/2008/12/bargain_hunt_external_hard_dri_1.php
Link 2: http://reviews.cnet.com/hard-drives/
Link 3: http://www.consumersearch.com/external-hard-drives
Link 4: http://www.pcworld.com/reviews/collection/1650/top_10_external_hard_drives.html