He really is an amazing saint. Saint Jude was the brother of Saint James the Lesser and a blood relative of Jesus. He is reported to have resembled Our Lord greatly in looks - hence the reason Saint Jude is sometimes pictured holding a medal of Our Lord.
Saint Jude is traditionally venerated as the patron saint of lost or impossible causes. This stems from the fact that his name is very similar to Judas Iscariot, the traitor. (A variant of Jude often used in the Bible is Judas.) Because of this similarity, people would confuse the two. They did not ask for Saint Jude's intercession, basically rendering him "a lost cause". (Things have improved since then. ;) )
Here are two of my favorite prayers to Saint Jude.
Saint Jude Prayer in the Morning
Saint Jude, giver of hope, let the promise of this new day fill me with wonder. Goodness surrounds me this morning. The sun rising to greet the earth recalls the joy of Easter morning, when Christ's light burst forth, showing the world His glory. St. Jude, place a spark of hope in my heart and ignite in me a fire burning with the love of God. Help me in my work today. Help me to forgive readily and to know and do God's holy and true will. May everything I am bring glory to God, and lead me closer to you, my ever-loving friend. Amen.
Saint Jude Prayer at Night
Come St. Jude, dearest companion. Quiet my heart and free my spirit. Help me to recognize the gifts of this day. I go now to rest. Refresh me this night with peacful sleep. Hold me and my loved ones close to you, keep us safe, and protect us from the evil one. Guide and heal my tired mind and body. Bring me safely to another day, that I may live to serve Jesus and walk with you in hope toward my heavenly reward. Amen
Saint Jude... pray for us!