This article originally appeared in Geospatial Solutions Magazine's Net Results column of September 1, 2003. Other Net Results articles about the role of emerging technologies in the exchange of spatial information are also online. 1. Introduction and Glossary   2. Whether, Not When   3. Practical Theory   4. Future Directions Every two years, since 1988, a small but international group of academic and industry researchers has been quietly exchanging their advances in spatio-temporal database technology. Who are they? What edges are they exploring now? Is a graduate degree required to comprehend their work? I had plenty of time to contemplate these questions on the long series of flights between San Francisco, California, and Santorini Island, Greece — site of the Eighth International Symposium on Spatial and Temporal Databases in July. The trip was well worth the expense. Except for solitary representatives from companies such as ESRI, IBM, Microsoft, Oracle, and Logical Information Machines, Inc., the attendees were professors and doctoral students driven more by curiosity than the bottom line. If you emulate them, your curiosity may also be piqued by questions such as: How can a database efficiently find the periods of overlap of time intervals having vague or unknown beginnings or endings? Given a historic collection of moving points, how can the database identify the area and instant of greatest point density? Of the many available indexing strategies, which will perform best with very large or volatile spatiotemporal datasets? How can databases identify outliers when statistically analyzing point data? What kind of handheld PDA interface best supports the combination of LBS and an event notification system for tourists? How can a central map server predict where a location-aware vehicle is going in order to preemptively send the appropriate map updates? This month, Net Results surveys several active spatio-temporal thinkers and discusses their latest discoveries in this complex, highly technical domain. Rather than attempt to cover any of their ideas in depth, we’ll just glance at the highlights, like sampling a box of mixed chocolates, in hopes of conveying the general flavor of today’s spatio-temporal research community. Glossary LBS: Location-Based Services PDA: Personal Digital Assistant TIP: Tourism Information Provider 1. Introduction and Glossary   2. Whether, Not When   3. Practical Theory   4. Future Directions