So, according to Google Earth, here's my walking distance while I was there:
<ol>Day:
<li>5.44 miles (just walking around)</li>
<li>1.83 miles (walking to the conference center and back...got a ride home)</li>
<li>3.66 miles (1.83 x 2 - walking to the conference center and back)</li>
<li>4.08 miles (walking around before my flight left)</li>
</ol>
That's 15.01 miles, total. When I see that it was only 15 miles, I'm glad I didn't rent a car or anything. That's perfectly walkable.