The head of soccer's global governing body told reporters that a FIFA committee was assessing various forms of technology but that whatever they plump for will be operational at the event next December.
FIFA are studying camera-based goalline technology as well as a "smartball" containing a computer chip.
The "smartball" was used at the under-17 world championship in Peru last year. The ball contains an electronic chip that sends a signal to the referee via a wristband or earpiece indicating when the whole ball has crossed the line.
"Next year we will conduct experiments in youth competitions (in Canada and South Korea)," Blatter told reporters.
"By December 2007 I am convinced we will be able to use one of them (forms of technology)."
Blatter underlined that goalline technology was the only form of technology he would sanction, ruling out any use of instant-replays.
"Video like this would take away the spontaneity and what is fantastic about football," Blatter said. "We want to keep the human element."
A result of keeping the "human element" was that mistakes would continue to occur, Blatter conceded, and he called for more respect for referees from players.
"It begins with education," he said. "We must educate our young players to respect the referees. Referees are an important part of our sport."
