I've always found these annoying and in my experience users never used them. The end/home and pg up/down keys largely provide this functionality from the comfort and speed of the keyboard. Less directly but more accessibly the scroll wheel and scroll bar provide more accurate and more universal functionality without cluttering your page at all.
More subjectively the top/bottom links always seemed near useless to begin with; what's at the bottom that I need? I know where the top of the page is, why are you giving me a link to it? A website inherited had a little javascript div that would follow your window and "pop" in to give you directions on the page. I couldn't get rid of it fast enough.
The one exception I've found is mobile sites, where I don't want to scroll all the way up, but often the problem there is lack of navigation; I scroll all the way to the bottom to be greeted with no nav bar. Good mobile sites often have a nav bar at both top and bottom.