An excellent write-up on one of the demonstrations performed during Jack Dangermond's opening plenary at the 2007 ESRI User Conference this morning appears on the ESRI User Conference Blog. The post, titled Integrating Online Geospatial Services Delivers Superior Visualization and Information, details the use of ArcGIS Explorer and ArcGIS Online. The write-up includes several screenshots of what was shown. If you are at the User Conference, make sure to stop by the Explorer showcase area to see these demonstrations again, and learn how you can do similar things with Explorer.