He's not only entertaining crowds with his music, but George Dennehy is inspiring them because he plays the guitar with no arms.Now he can say he performed with a Musikfest headliner.Dennehy played the song, 'Iris' with the Goo Goo Dolls Tuesday night.It's a song he first uploaded to the web, which made him an Internet sensation.Even though he was born with no arms, Dennehy says his mother helped him learn to play cello at 8 years old."My mom saw Tony Melendez one time in a video or live. He's another armless guitar player and she went up to the teacher and said, 'If Tony Melendez can play gui