There are over 10,000 athletes competing in the 2012 Olympics. I have not even found a link that lists them in a single location under individual names. See related link
104 athletes are competing in the Olympics games for Brazil 2012
Yes. Vietnam is competing at the 2012 Summer Olympics in London and has 18 athletes competing in 11 sports
Slovakia has 46 athletes competing in the 2012 olympics
Wikipedia list India as having 81 athletes competing in the 2012 summer Olympics
Over 10,000 athletes from 204 countries will be competing in the 302 events for the 2012 London Summer Olympics
At the 2012 Summer Olympics in London the Philippine's is represented by 11 athletes who are competing in 8 sports, making it the smallest Philippine delegation to the Summer Olympics since 1936.
Wikipedia lists Germany as having 391 athletes competing in the 2012 Summer Olympics in London
The country with the most athletes competing in the 2012 Olympics is Great Britain. They have a total of 558 athletes.
Wikipedia lists Italy as having 284 athletes competing in the 2012 Summer Olympic Games
Ireland is competing at the 2012 Summer Olympics in London, United Kingdom with 66 athletes in 14 sports
there are 30 athletes competing in the London 2012 games.