Welcome to Gaia! ::

It's something that'll probably be a big deal in the last book, among other things. He wasn't able to do it OotP *or* HBP, though in HBP Snape was simply blocking him; obviously Harry's attempt was weak enough to be blocked.

I think that he'll try to learn Avada Kedavra, only to kill Voldemort, and after that vow to never ever attempt to cast the spell again. Harry's a very "Me no keel other ppl" character; he'll try to do anything to avoid killing another person.

I don't think that Harry will ever pull one off, I can see him trying and maybe even training but I doubt he'd ever be able to do it. Like Ernie said, he's not that kind of character. Harry has a lot of pride, and it would be against his morals to stoop down to Voldemort's level and use a unforgivable on him.
I, personally, think that Voldemort will discover that there is a fate worse then death before he dies (if he does).
EDIT: Interesting, at the moment it stands 3 no and 4 yes. I wonder if that will change soon.

Woohoo, 'Nari's actually posting in a discussion!

*Ahem* Back on topic. I think that the whole point of the books is good(love)>evil(hate) and Harry using an evil curse, fueled by hate, to kill Voldemort would be pure hypocrisy at least. It's the whole "bombing for peace" thing all over again. Harry has to do away with Voldemort via love or the books will have no meaning.

/my two cents.

I think that Harry might actually suceed in using an Unforgivable Curse against Voldemort. Because when he was fighting Bellatrix at the Ministry in OotP, he tried to use an Unforgivable on her, but it didn't work. She said he had to mean it, sheer anger wouldn't work. But with Voldemort it's different (at least for Harry). You never know. *shurgs*.

Darn you, I was all prepared to write a big eplaination based on that exact topic. I will anyways, but don't think I'm trying to steal your fire lol

Anyways, looking at the series itself and not necessarily at the characters in it, we see that there is this deep underlying battle between good and evil, love and hate, friendship and enemies. These things often get blurred in points (especially in HBP were we see a whole new side of Draco), but the core battles are still there. I would be SHOCKED if JK Rowling decided that the best way to destroy evil (Voldemort) is with evil (Unforgivables). I really think that Harry will have to realize the great importance of love, like Dumbledore was trying to stress on him all through the first 6 books, and learn how he will have to use that power against the power that Voldemort has, hate. As much as I hate it, I have a feeling that Harry will have to make some sacrifice or choice when it actually comes down to killing Voldemort. It won't be as simple as sneaking up behind him and muttering Avada Kadavra. It will have to require some loss on the part of Harry. I haven't decided (or wanted to admit openly) that Harry might have to chose to sacrifice himself or something/someone close to him for the greater good of destroying Voldemort. Ironically, despite the controversy in the media, there seems to be a faint underlying theme in the Harry Potter series that is reminisent of the Jesus story. I'm not a follower of the Catholic faith so my facts may be a bit rusty, but the whole "ultimate good sacrificing themselves to rid the world of evil" just sounds way too familiar to overlook.

So I guess, getting to the point, I don't think that Harry will destroy Voldemort with an Unforgivable Curse. He may attempt to use one, but realize that is not the course things have to take, and find a way to use the good/love/purity within himself to accomplish his task.