1966???? I think the last time the Beatles performed together as a foursome was January 1970 on top of the Apple building in Saville Row, London.
Ok, the latter wasn't technically a stage...
George and Ringo did play a few times together after the band broke up - definitely once at the 1987 Princes Trust concert in Birmingham, and defintely at George Harrision's solo concert at the Royal Albert Hall in 1992 just before the UK general election (George was a supporter and campaigner for the Natural Law Party - this was a kind of charity gig I seem to recall).
Obviously, in the 1990's Paul, George and Ringo recorded again for the Beatles Anthology project (with mixed results - one song was barred from being released by George by all accounts as it was pretty grim), and they had both contributed to George's 'All Those Years Ago' single in 1981 (albeit from afar and by posted contribution from Paul) that was written to celebrate the times they had after Johns death. Interestingly, George invited Linda McCartney and Denny Laine from 'Wings' to play on the song also, as well as having George Martin produce the track.
I think it was just a media 'wet dream' to have the band reform, with Julian taking Johns place for Live Aid (how could the poor lad ever live up to his fathers memory - it would have been a disaster). In reality, it was never ever ever a genuine runner.
Moving on to Live 8, what I want to know is how we get Pete Doherty's mind back from wherever it is. Does the world have enough money to do it, or do we need another charity concert to raise sufficient funds?...