ImpromptuDo is an interesting experiment in presenting time based events listings. It allows users to find events happening around them right now or lets them plan ahead and find events happening later.
ImpromptuDo is a Google Maps based application that can show you events happening around you based on a set number of hours. Using the map you can centre on your current location. You can then use the slide control to view events happening within the next 1 to 24 hours.