Freeview is searching for 450 volunteers in London to take part in a six-month trial of high-definition TV broadcasts through the free-to-air digital TV service.
The BBC and ITV will offer HD broadcasts of live World Cup matches during the trial period. Other shows will also be made available in the format.
To take part, viewers need to own an HD-ready TV set. Potential users can apply online to take part in the trial.
Telewest and Sky are both launching HDTV services this year.