Here's an interesting paper in press with Acta Astronautica by two of our planetary protection mavens:

Got life? Hours of boredom followed by moments of sheer terror (and that's just with the press)
Acta Astronautica, In Press, Corrected Proof, Available online 25 July 2006
J.D. Rummel and M.S. Race
Abstract

Note: If you haven't done so, check out the recent interview with Rummel on Planetary Radio. And if you have old issues of The Planetary Report, check out the debate from a six years ago that stemmed from an Opinion piece by Robert Zubrin entitled "Contamination From Mars: No Threat," which generated three rather "vigorous" responses:

* "A Case For Caution" - by John Rummel, Ph.D., Planetary Protection Officer, NASA Headquarters
* "Hazardous Until Proven Otherwise" - Margaret Race, Biologist with the SETI Institute
* "Practice Safe Science" - Kenneth H. Nealson, Director of the Center of Life Detection, NASA/JPL

And Rummel's response will help explain his comment on Planetary Radio about Zubrin