The Patron Saints Index lists St. Philip Neri as a patron of Rome and a couple of other Italian locales, and as a patron of the U.S. Army Special Forces. (I'd be interested to know the reason for that last one.) To me, however, he is a patron saint of friendship.
I discovered Neri a few years ago when William Newton generously passed on to me his copy of Paul Turks' biography Philip Neri: The Fire of Joy after I admired it on his shelf. The saint's name was familiar to me from hearing an anecdote of his life read at Dominican House of Studies' Vigil of All Saints; the story was about how Neri used to make people laugh by walking around with his coat inside-out or with half his beard shaved
Reading the biography, I was struck by how, although Neri had an intense intimacy with the Lord, he was always reaching out to connect with others, drawing them through his own friendship to the love of Christ. I had recently moved to Washington and longed to make close friends in my new home. What was more, I needed help learning how to be better devoted to the friends I had. So, when I went to Mass—which is the time when we are nearest to the saints, being united with them in the Eucharist—I began to ask Neri's help, telling him my needs and asking for a share of his gift of friendship.
My prayers were answered, more quickly than I expected. I still ask St. Philip Neri's help for becoming a better friend, but no longer feel the loneliness I felt upon coming to D.C. Good people have found me, no doubt with the saint's help—friends who love the Lord, and who help me draw closer to him.
There is a misconception among non-Catholics (and even, I think, among some Catholics) that saints' intercession is limited to one-time blessings, like a miraculous healing, or a parking space in Georgetown. Although I do believe that God often chooses to work such miracles in answer to the saints' prayers, the greatest intercession I have experienced from saints has taken place over time, as they have walked with me and helped me through everyday struggles. Heavenly friendship is much like earthly friendship in that way.