Me to because I see this as the key feature of the idiocy and weakness of US "news" media. Moore is a liar because some conservative who did not like his opinions said so often enough that it became a part of the "official" public record
I'm not conservative, and I think that Moore is dishonest. He might be able to say 'its not technically lying' but he is still dishonest. If you think creationists are dishonest for quote mining, then so is Moore (a master quote miner), if you think skipping important context is dishonest, then Moore is dishonest.
I believe somebody once said of Moore 'you shouldn't have to lie to tell the truth' and I pretty much agree with that sentiment.
A quick example (I think from Farenheit) is Moore talking about the coffin ban in a way that would lead you to think that it was Bush Jnr's idea to ban the photos. He neglects to mention an important fact: that the ban was imposed in the first Gulf war by Bush Snr due to reactions from the Servicemen's families. He also neglected to mention that the specific directive that was used was penned by Clinton in 2000. Finally he didn't mention that the military has its own restrictions about photographs that have been in place since before either Directives. The interesting fact that Moore should have discussed was the inconsistency of applying the ban (ie when it was convenient to ignore it, it was ignored and when it was convenient to enforce it, it was enforced).
Another example: After Bowling... I went away thinking that Charlon Heston was an cold hearted racist. Why did I think that? Because Moore spliced several comments by Heston together totally out of context and time from the incidents being discussed (the shootings).
To me, that is dishonesty pretending to be honesty (technically no lie has been made, but good faith has been betrayed by ommision rather than by commision). Moore can (and has) weasel out of it by claiming he didn't intend for the viewer to be fooled.