The Walt Disney Company is the latest firm to invest in online video aggregator Hulu, saying this morning that it has agreed to join NBC Universal, New Corporation, and Providence Equity Partners as a joint venture partner in the site. According to Hulu and Walt Disney, it will become an equity owner in Hulu, and also distribute its current and library primetime series and feature films through the site. Financial terms of the deal were not disclosed. The two said that full length episodes of such series as Lost, Desperate Housewives, Grey's Anatomy, Ugly Betty, and more will all be streamed on Hulu's ad-supported service. In conjunction with the equity investment, the firms said that Disney will take three seats on Hulu's board, adding Disney's Robert Iger; Anne Sweeney, who is co-chair of Disney Media Networks and President of Disney/ABC Television; and Kevin Mayer, Disney's EVP Corporate Strategy, Business Development & Technology.