This script submitted by Julian Lannigan will calculate the time taken of a given file size accross connections ranging from 9.6k up to 128k (ISDN) connections and display the time in seconds, minutes and hours. All colors can be changed to suit your site. Unfortunitly this script does not work in NS4+ browsers, however it works fine in NS6+ and IE5+.
Color config is listed below, it is also included in the script.

Under "bgcolor" you will find "color" this is the font color of rows 3-8.
Under "bgcolor" you will find "background" this is the background color of rows 3-8.
Under "bgcolor" you will find "font-family" this is the font type of rows 3-8.
Under "bgcolor" you will find "font-size" this is the font size of rows 3-8 (keep th 'px' at the end).
Under "bgcolor" you will find "font-weight" this is the font weight of rows 3-8 (choose between bold,normal).
Under "keys" you will find "color" this is font color of the buttons lettering.
Under "keys" you will find "background" this is background of the buttons.
Under "rec" you will find "color" this is font color of rows 1-2.
Under "rec" you will find "font-family" this is font type of rows 1-2.
Under "rec" you will find "font-size" this is font size of rows 1-2 (keep 'px' at the end).
Under "rec" you will find "font-weight" this is the font weight of rows 3-8 (choose between bold,normal).
Under "rec" you will find "background" this is the background color of rows 1-2.