re: Further evidence for current liquid water near the equator on Mars.
Note that recent theoretical research suggests liquid water might
indeed be able to exist in some regions of Mars for short times:
Meteorological Control on the Formation of Martian Paleolakes.
http://adsabs.harvard.edu/cgi-bin/bib_query?2000LPI....31.1509H
Some of the areas were near the equator, however the authors ruled out equatorial areas because they were believed to be desiccated. This Mars Odyssey evidence suggests water does in fact exist near equator and therefore could become liquid for short periods seasonally:
Bob Clark