I have bad luck when it comes to laptops (or perhaps as the Apple tech said, I work my laptops harder than 99% of the users out there). It seems I have experienced data loss a few times to many and I finally sat down and figured out a back-up strategy. So you can save yourself a headache, I offer you my workflow to achieve data nirvana.
1. Get a small, high-quality drive that you can take with you. My choice was to get an OWC Mercury On-The-Go case. There are four different options to choose from and they each offer connection options that are impressive. My choice was to get the case only and drop in a SATA laptop drive. I was able to get a 160 GB drive that is big enough to hold the contents of both my MacBook and MackBook Pro. (If you are curious... the MBP is my small writing/blogging machine while the 17 inch is for teaching and production... 17 inch laptops and coach seats don't go together.)
2. Get backup software like Data Backup from Prosoft. I like this package because its affordable and I have had great experiences with the company's other software like Data Rescue and Picture Rescue. This package allows you to Clone your drives and make a bootable image so you can easily restore files. My favorite feature is its robust scheduling tools including the ability to have a backup start whenever you plug in the backup drive. Simply set the program to automatically open as a login item (right click on its icon in the Dock at choose Open at Login). Then choose to set a schedule and set an event for the presence of the backup target.
3. Remember to plug-in the backup drive