@ Yellowjacket
Forgive me, but those examples you list of educational successes seem to be focused on issues where the parents are likely to be either in support of the school or showing little interest either way. For subjects such as homosexuality, where some parents (and, indeed, older siblings) will provide the child an actively opposing view, the results may be very different. Even if not the idea of setting teachers against parents in an ideological conflict seems a poor strategy at best.
No, one cannot round up all parents for remedial classes in modern ideas of civalised behavoir, but that is not the only way of educating adults. A few high profile ministers taking part in a gay pride march, for example, or advertising of the problems presented by discrimination on TV would be a useful start.
Ultimately, however, the largest impact can be made by the gay community itself. The progress that could be made, for example, if we had a few openly gay footballers would be huge, as football crowds are one of the last bastions of open homophobia. Sadly, however, none of them are willing to risk their easy livestyles for the sake of making a difference. Understandable, perhaps, but disappointing that they have been unable to show similar levels of courage to the likes of, say, Stephen Fry.