Here is a way to select the fastest Debian Mirror:
(subsitute your version for etch in the examples below)
# apt-get install netselect-apt
# netselect-apt etch
# netselect-apt -n etch
# netselect-apt -n -f etch
Link to full article (change the _com to .com) http://linuxhelp.blogspot_com/2007/05/using-netselect-apt-tip-to-select.html