Is there an easy way to change the graphic for the "average rating" that appears for each product or do I have to go database diving again?

If you have a look at the page source (Firefox = Control+U) you will see it displays a gif in /images/(your layout)/ rating_x.gif where x corresponds to the rating number.
A quick tweak of those should change the graphic or you could look at the other design layouts to see if an existing one is more to your taste?

Thanks! I ended up editing the template pages to pull the image from my custom template image directory. 5 custom images later and I have a beautiful rating system in place! Cool stuff!

Sounds interesting. Would you like to publish your URL to share this with us?

iceman please don't edit the template pages directly. As from 3.5 _copy_ the ones you need to change to a new folder in templates and change the template folder to this in Administration > Layouts. This way you wont overwrite your changes if you upgrade.