Today is April Fool's Day so be wary of hoaxes and practical jokes, especially at news sites.Despite the date, rumors that Mac OS X Tiger will be announced today have not changed.Real announcements are sometimes made on April Fool's Day, such as Google's announcement of Gmail last year. Apple Computer itself was founded on April 1, 1976, with today being its 29th birthday.However, even respected web sites sometimes post humorous or misleading stories in recognition of the April Fool's tradition, so be especially cautious about the accuracy of news you hear today.