Blue Marble Geographics (http://www.bluemarblegeo.com) sells a Geographic Calculator that will convert between just about every projection/datum ever used. It's not particularly cheap but it works well. BioLink (http://www.ento.csiro.au/biolink, the normal address http://www.biolink.csiro.au is currently broken) also converts between UTM and lat/long (using a number of datums). Steve Shattuck