As I noted in my last post, UD has an ArcGIS Online subscription. As part of that service we have credits to be used (frugally) towards geocoding. Just let me know you are interested, and I'll sign you up. You'll receive an email with details about logging in and completing the sign up. Instructions for pointing to the service from ArcGIS, with a link to instructions on geocoding a table of addresses, is here: http://resources.arcgis.com/en/help/main/10.1/index.html#//00250000004v000000
Geocodes cost UD 1 service credit per 25 addresses. If you would like to geocode more than 100 addresses, I may refer you to other options for geocoding.