Blocking the Unblockable Curse.

This is mostly related to canon, but also a bit to HPMoR.

I've always wondered why the killing curse counts as "unblockable". In "Order of the Phoenix", Dumbledore blocks it by moving a statue in its path. Seems to work nicely. There is other evidence that solids stop the killing curse -- if it went through it, you could accidentally kill somebody behind a wall when missing your target. Prof. Moody would surely have mentioned that danger when talking about the killing curse, if that was the case. So you could carry around a steel plate strong enough to block the curse, and quickly move it into its path. Not easy, but possible.

There are also several instances where simple spells conjure animals (I remember bats and small birds). I wonder if you could simply conjure an animal into the way of the killing curse. It might need to have a minimal size to work, but a powerful wizards should be able to do that.

I also wonder if there are ways to combine charms: one detection charm that triggers another one. For example one that detects killing curses, and enables apparation or a portkey.

So, one proven way to block a killing curse, one conjectural, and another conjectural way to escape it. I can't believe the wizards still call it "unblockable" :-)