[lostlogin]

Personally I find it useful when it says it was an hour ago, or a day ago, or 3 days ago etc up to a week. Then the date is what I want.

[cynwoody]

Yes. And it also helps if it's near the top of the post, as opposed to being buried in a signature or something.

Bottom of the page would be OK, too, if people always put it there. But they don't.

Consistent date placement promotes efficient search engine result scanning (Google's date constraints are highly imperfect).