I stumbled into the bear barrel strategy last year.  I was at the REI scratch&dent sale and scored a smallish bear vault on the cheap.  I'd always been a 'hang em high' kinda guy, but for the money I thought I'd give it a shot.

1st, let me say it's great on a solo because it holds a weeks supplies nicely.  Also, it is nice to have one less chore on a solo.  I enjoy a lot of the camp work, but the pack hanging can be a hassle.

As for as location, I agree with others that have said to be careful about where it might roll off to.  I would stash it in such a way that it was fairly visable from the direction of camp, just so when I was trying to find it I'd have an easier time.

Here's my question, how far is far enough away?  I've always struggled with this when hanging or stashing.  My rule of thumb has been, go until you think it's far enough, then double that distance.  So far, never had a bear in camp...