Last Updated: Monday, 3 October 2005, 10:58 GMT 11:58 UK Yahoo is taking on Google with its own digital archive of books, audio and video. As part of the Open Content Alliance, Yahoo will help digitise 18,000 works of American literature plus material from national and European archives. It hopes to avoid the legal action that has dogged Google's plan by adopting an opt-in policy on copyrighted wo