Diigo, Twitter, and Pinterest are the most useful social media tools for educators according to the document. Diigo allows users to highlight and add notes to any website or article and share resources with other professionals. Twitter is good for collaborating with other educators and staying up to date on research. Pinterest enables educators to share ideas and participate in an educational community. However, managing multiple networking sites can become overwhelming and it is challenging to gain followers on Twitter and Pinterest. The document also notes that while there are many educational resources available, there is not enough time to explore them all.