Different journals and journal publishers of course all have their own contributor agreements and differing copyright policies. But most have something to say about authors' rights and, in particular, some degree of restriction on rights of reproduction or distribution of their work once its published in a journal. At the same time, clearly most academics these days do distribute these things personally or often even post them on their personal or institutional websites.
One journal publisher I have experience with seems to allow re-posting of the final 'version of record' by its author so long as all atribution is made, and allows for this to happen immediately. Another allows re-posting only of the author's final version as submitted (pre-typesetting, pagination, publication, etc.), and even then only after waiting 12 months; they explicitly forbid ever posting the version of record outside of the paywall without appealing (and paying) for open access.
Setting aside my own beliefs about open access (though note neither of the above are Elsevier), and without getting mired in too much copyright law (though I suppose this would be welcome too if anyone's up for it), I'm hoping to gather other people's experiences and impressions around this practice. Does everyone just post these things anyway? Do people make nice semi-final (but not copyrighted) versions of their articles to post even after publication? What sort of trouble could one get in for posting the copyrighted version on one's personal webpage? How ok is it to say "email me for a copy if you don't have institutional access"?