How do I create an ideogram-based 'features' list on nodes? I'd like to create a simple checklist-style list on a node. How can I do this?

I presume CCK is involved. I'm thinking that it would follow some logic like this: the node editor checks applicable boxes for the relevant feaures. If a box is ticked, then an image is displayed in the list (and so on) on the node.
If you get a Drupal 6 specific answer, that's great, but in the meantime, I would suggest you look at this question. It involves Drupal 7, but the basic principal is the same. If I have had the experience of doing this in D6 I would have added the information to that question, but I have not.