If you're burning to standard CD-R or CD-RW discs then you might be surprised to find that your data (images) will only be good for about 2 years.  If you've been good and stored those discs in a dark spot then you might get 5 years out of them.   Here's an article with some more details on why the discs aren't your best choice for archiving images.

If you notice at the end of the article they give some info on some discs that offer 100+ years of archival storage, but at a slightly higher price that standard CD-Rs or CD-RWs.  The discs contain gold, and we know gold isn't cheap.  I was able to find the discs here:  amazon.com for a little more than a dollar per disc.  So more expensive than regular discs, but still not crazy expensive.

With the price of hard drives dropping to less than fifty cents per GB it's not unreasonable to have a separate drive for backing up images and videos.   With 200GB drives selling for less than $100 you can use a drive for back up and then store it in a fire proof safe between backups.  A removable drive cage works great for this, or you can find "external" hard drives that connect via USB2 or Firewire for $20 - $30 more than standard hard drives.

Another option is using an online backup service.  With these services you backup your files to an off site server.   There are quite a few of these services available now, as a quick search turned up ibackup.com  and evault.com.  These might be a good solution for short term archiving, but will your data still be accessible in ten or fifteen years?

 Also keep in mind that file formats change and so you can't just put for images into PIC format (an old b&w format used by Atari computers way back when) and expect to find a program that will read them ten years from now.  So the JPG, TIF, and PNG images that you're saving today will need to be opened and resaved in a new format at some point or you'll risk not being able to open them eventually.