It's used in fire spread prediction models and land use/urban growth models among other things.

SLEUTH is one such model adapted from a fire spread prediction model. We used it in modeling urban growth in the NYC region 2 decades ago, so it might not be the latest and greatest CA out there for urban growth. We calibrated the model on 1930 - 1980 data and validated it on 1990 and 2000 data, projecting into the 2050s for A/B scenario growth in the IPCC report of the period.

SLEUTH home: http://www.ncgia.ucsb.edu/projects/gig/