In addition to being able to tag people using the @ function, how about a Tag link in each post next to the Reply link?
What that would do is tag the member in the same way but it would insert in the post like this:
Code:
[tag="xfrocks, post: 330459, member: 2880"]xfrocks[/tag]
And instead of opening the member profile page when clicked, it would load the post from which the Tag link was clicked, in the same way the quote attribution works.
So this wouldn't replace the @tag function, it would be in addition to, if you wanted to tag a member from a specific post.