I know that I may just have to link the image to make this happen, but I figured it was worth asking, just in case there's some other semantic markup or tips I could use...

I have a site that uses the textual Creative Commons blurb in the footer. The markup is like so:

<div class="footer">
    <!-- snip --> 
    <!-- Creative Commons License -->
    <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/3.0/us/"><img alt="Creative Commons License" style="border-width:0" src="http://i.creativecommons.org/l/by-nc-sa/3.0/us/80x15.png" /></a><br />This work by <a xmlns:cc="http://creativecommons.org/ns#" href="http://www.xmemphisx.com/" property="cc:attributionName" rel="cc:attributionURL">xMEMPHISx.com</a> is licensed under a <a rel="license" href="http://creativecommons.org/licenses/by-nc-sa/3.0/us/">Creative Commons Attribution-Noncommercial-Share Alike 3.0 United States License</a>.
    <!-- /Creative Commons License -->
</div>

Within Google Webmaster Tools, the list of relevant keywords is heavily saturated with the text from that blurb. For instance, 50% of my top-ten most relevant keywords (including the site name):

1. [site name]
2. license
3. [keyword]
4. commons
5. creative
6. [keyword]
7. alike
8. [keyword]
9. attribution
10. [keyword]

I have not done any extensive testing to find out rather or not this list even matters, and so far this doesn't impact performance in any way. The site is well designed for humans, and it is as findable as it needs to be at the moment.

But, out of mostly curiosity: Do you have any tips for decreasing the relevancy of the text from the Creative Commons footer blurb?