BBC will launch its iPlayer in a month, meaning the public can download their top shows online up to a week after they screen on TV.
The revolutionary service will initially only be availble on Windows PCs, but the BBC says Mac users could access the iPlayer by Autumn.
Later this year, the service will also be available via links from YouTube and could also appear on other websites such as MSN, Bebo, and Facebook.
Eventually, other features will be added, including live streaming of programmes, the BBC Radio Player and ‘series stacking’, which will allow users to download episodes from series retrospectively.
Director General Mark Thompson said: “In our view, the iPlayer is at least as big a redefinition of what TV can be, what radio can be, what broadcasting can be, as what colour television was 40 years ago.”
iPlayer will allow viewers to catch up on TV programmes for seven days, while some TV series can be downloaded and stored for 30 days and viewers will be able to watch shows streamed live over the internet.
Programmes will include popular series such as Life on Mars; soap operas such as EastEnders and documentaries such as Planet Earth. Initially, 400 hours of programming will be available.
Some sporting events, such as Euro 2008, will be offered through the iPlayer as the service expands.
Over a 2MB broadband connection half an hour of programming will take approximately half an hour to download.
Once viewed in entirety, programmes will be automatically deleted.