ceramic water filter element

how does the ceramic water filter element in filters like the MSR mini-works actually *work*?

In the most basic terms, the ceramic material is full of very small pores which allow water to pass through, but block most contaminants -- silt, bacteria, etc. The MSR filters (and presumably others) also contain an inner carbon filter which removes many chemical contaminants.

More info (and pictures!) here:

http://www.msrcorp.com/filters/ceramic.asp
http://www.campingsurvival.com/aqwatfil.html