If the page scrolls that won't keep the block at the bottom of the page in most browsers.
In modern browsers position: fixed will do it but IE stumbles here, though I think IE7 understands it.
Position: fixed will make something stick, so it won't scroll with the page. You can 'fix' it anywhere and it won't move. Now IE7 supports it I assume we'll have a gazillion pages with 'stuck' content on them for no reason in a year or so!