Power Rangers come out at scheduled times of the day in Hollywood Studios. Check your guide and then try to line up for whatever character you want a photo of before they get there. The park photographers will help you.
Phineas and Ferb are the newest characters in Hollywood Studios. Be prepared, the line is in direct sunlight so we were really hot by the time we had the photo taken. Handy Manny is at breakfast at Hollywood and Vine and in animation courtyard. His line can get rather long, but it moves quickly. If he takes a break don't leave. He will be right back.