Terry Tao on Ultrafilters, and nonstandard analysis

Back in 2007 Terry Tao (Fields medalist Mathematician at UCLA) wrote a blog article on Ultrafilters, nonstandard analysis, and epsilon management.

Since I'm interested in nonstandard analysis as a tool for building mathematical models of physical systems, I'm going to recommend that if you're interested in the same topic, you should go read his post. After I'm done reading it, i'll come back here and give some links to people actually using nonstandard analysis for modeling.