UK is going to host a major competition before the 2012 London Olympics: the 2011 World Championships in Trampoline, Tumbling, and Double-Mini Trampoline! It will be at the National Indoor Areana in Birmingham. It will be the qualifying competition for the 2012 Olympics.
3 days competition, 650 gymnasts from 40 countries expected.
Other major competitions there have been: 2004 World Cup Finals in Artistic Gymnastics, and 2006 World Cup Finals in Trampoline and Tumbling.
"UK to host key gymnastics event
Birmingham has won the right to stage a major international gymnastics event ahead of the 2012 London Olympics." -
http://news.bbc.co.uk/sport1/hi/other_sports/gymnastics/6675817.stm