Today, New Scientist and researcher Ron Levin retracted the "puddles on Mars" claim in the face of evidence that the "puddles" were on sloping surfaces. I've updated my original blog entry in response to the claim to that effect.
Several readers have pointed out to me a lovely image that also puts the location of the alleged "puddles" into its properly steep context, an image that includes a simulated view of Opportunity tiptoeing onto the slope to examine it up close. Here's Opportunity's original Burns Cliff panorama, in which, as is usual for such panoramas, some parts of the rover's deck are visible at the bottom of the image:
And here's the one that's been tricked out with a model of the rover to scale with a more distant part of the panorama. The image really helps you to see how the walls of the crater drop away from the rover's point of view on sols 287-294 -- and how the rover was tilted as it explored this surface.
Although beautiful, all of this is old news; for the latest on the Mars Exploration Rovers, you should read A. J. S. Rayl's detailed coverage of their activities.