"Friendship, friendship, just a perfect blendship"--so wrote Cole Porter for the musical DuBarry Was A Lady--a song and a sentiment we all can harmonize with. We all have friends, and if some writers have been more than a bit cynical--Emerson thought that friendship resembled the immortality of the soul "in that it is too good to be true," and Schopenhauer compared friendship to a sea serpent, "no one knows whether they are fabulous or really exist...