You can discover the location of an online Skype user using this approach:
1) Verify if the user is really online;
2) Go to https://www.hanzresolver.com/skype2 and put the Skype user name;
3) It will return: Resolved IP: xxx.xxx.xxx.xxx (2156ms);
4) Go to https://www.maxmind.com and put this Resolved IP number in the “Try our GeoIP2 Precision service demo:” text box and click on “GO”.
5) It will return a Lat/Long position like this: -23.5475, -46.6361
6) Just search for this lat/long on Google and it will return the map position.
Very easy!
Update: The position is not precise, it is approximate. It should be probably the “last mile” position from your ISP.