There are currently three ways to add geographic decimal coordinate (longitude and latitude) columns to your data for map displays:
1.) Merge the columns into your Omniscope data automatically using a merge file. To merge in coordinate columns for capital cities or geographic centres of countries, we supply free 'By Countries' merge file containing these columns. We also supply a free 'By Cities' merge file containing coordinates for about 60,000 of the world's largest cities. Free merge files 'By Post codes' are also available for the U.K., the U.S., and a growing number of other countries. Other free and licensed reference merge files are available from data vendors. See http://www.visokio.com/merge-files for more information and to download files.
2.) Locate your records in Omniscope using the free Visokio world, country and city maps- just place the markers manually to generate the coordinates in the file automatically (see Placing Markers in the KnowledgeBase section on Maps & Coordinates (http://www.visokio.com/kb/maps) or
3.) Look up missing coordinates using online sources such as Google Earth (and often Wikipedia). In Google Earth, look up the missing places, set a placemark, then read off the values, then type/cut-and-paste them into Omniscope.

To learn more, see the User Guide sections on Using Maps and Using the Map View, and the KnowledgeBase sections on Maps & Coordinates.

Thanks Tom - I will try option1
I have too many unique cities to manually pinpoint by hand - so 2 & 3 are out (I had already read KB).
Stuart

Note - Omniscope now has geo-lookup formulae functions that allow you to geo-code using both open-source and commercial online search services, as discussed here:

http://forums.visokio.com/discussion/comment/1259/#Comment_1259