Marshall Hamburger has made it through to the grand final of Channel Seven’s Australian Idol overnight. The self-confessed “geek” joins 16-year-old Gisella Colletti from Western Australian, and 17-year-old Iilysh Retallick from New South Wales, in the show’s top three. Hosted by Ricki-Lee Coulter and Scott Tweedie, Marshall has been a popular contestant with his brilliant