There is a way to reach the High Charity Conduit on the final section of the level High Charity on Halo 2.
To do this, play the level until reaching the chapter called "Once More, With Feeling", and turn to either your left or right. You should notice a crate. Jump onto it and then crouch jump onto the Conduit. From here you can walk to the glowing start of the Conduit, or complete the level without fighting at all by walking the other way. This could be considered an easier way to achieve a speed run, although a generally unacceptable one.