World Cup competitions usually run from October through September of the following year but this year's final will be later due to the Sydney Olympics. In the 91 years since the Nations Cup was initiated, more than 1000 Nations Cup events have been held in 37 countries. The countries with the most wins are Germany, Great Britain, France and the United States (in that order). The US won the Nations Cup Final in Calgary Canada in 1997. France won in 1998 (Donaueshingen, Germany) and 1999 (Gijon, Spain).
There are 29 events in 26 countries in the 1999/2000 series. Two events are held per country in North America and one per country in Europe. Italy is the exception, hosting this season the Pavarotti International in Modena, the regular (May) Piazza di Sienna event in Rome, and the Nations Cup World Final (October), also on the Villa Borghese's Piazza di Siena grounds
Eight teams are invited to the Nations Cup Final, the top six in the point standings for the regular season and two wild cards allocated by the Nations Cup Committee. At the World Final, all the teams start from scratch.
The Piazza di Sienna events are climaxed by the famous precision horse drill, the Carosello dei Carabiniere -- 100 mounted Carabiniere charging around at full gallop -- which is scheduled as part of the last day's closing ceremonies.
Daily tickets can be purchased at the entrances of the grounds. There are several classes of tickets, with the more expensive ones on the southwest side of the grounds and the cheaper seats on the northeast. Ticket booths in May were at the Sea Horse Fountain, at the Children's Theater, and at the southern end of Viale Canonica, all inside the Villa Borghese park. CAUTION: tickets in May were for one entry only -- you could not leave and reenter on the same ticket.
Italian TV coverage throughout the May event was very good. Food was available from a cafeteria and a very expensive restaurant. Lots of horsy stuff was on sale from concessionaires.
Italian Equestrian Sports Federation (FISE) News (in Italian): http://www.fise.it/nuovo%20sito/so3.htm
Mr. Horse: http://www.mrhorse.it/
Horse Click (US): http://www.horseclick.com/
eQuestrian (UK): http://equestrian.co.uk/