"Roddenberry had first proposed a Star Trek feature at the 1968 World Science Fiction Convention. The movie was to have been set before the television series, showing how the crew of the Enterprise met"
http://en.wikipedia.org/wiki/Star_Trek:_The_Motion_Picture
imagine how cool it wouldve been if they had done something like the 2009 film and released post TOS season 3 in late 69 or 70 - with a modest budget (about $2-3 million) and Shatner, Nimoy, Kelley etc playing younger versions (could they have got away with it..? maybe been better off doing a follow up to TOS set shortly after Turnabout Intruder. Like Generations )
obviously wouldnt have needed the time travel aspect (but maybe they still couldve done that) and while Spocks backstory probably wouldnt have been that different to how we saw it in the eventual film, Kirks would have been (taken from backstory hinted at throughout season 1 and 2) - Kodus, Sam, Finnegan, Gary Mitchell, Finney, Ruth, the Farragut, cloud killer etc (although no Carol Marcus or KM test which wasnt introduced until TWOK)
Jeff Hunter could’ve appeared in a cameo at the end to hand over the Ent to Kirk (as told in The Menagerie. Maybe JH couldve filmed it just before he died. Crazy to think he died so young). wonder who the main 'Nero' villain wouldve been back then - maybe some up and coming film actor - Gene Hackman? (was in SF tv stuff like The Invaders around 1967 but then but broke into movies in about 68 - Bonnie and Clyde)
kind of like the Batman movie they made in 1966. they couldve gotten one of TOS directors to do it or even Robert Wise back then. With Roddenberry and some TOS writers (GLC) and maybe even Rod Sterling thrashing out a script. FX wouldve been Ok (better than TOS) but not '2001' standard which had a massive budget and Kubrick innovating new techniques, Alexander Courage or even Jerry Goldsmith or John Williams couldve done the score. Title – simple 'Star Trek'
it might have been HUGE at the box office what with the Moon Landing - maybe itd have kick started the Sci Fi movie boom in 69 or 1970 instead of 1977