A GreaseMonkey script for making tables on web pages sortable, also available as a Bookmarklet.
When activated, TableSorter automatically detects any tables that are displayed as you surf the web, and adds some links near the top of each table allowing you to sort its contents. Links appear at the head of each column in the table, so you can choose which set of values to use to sort the data. You can also choose between alphabetic and numeric sort, as well as selecting the direction (ascending or descending), and it's easy to revert the table back to its original order at any time.
You can try TableSorter right now, without installing anything, by using the live demo on the project home-page
Use the 'alpha' link to make the table sortable alphabetically, or the 'num' link to sort the table using any numeric values that appear in the columns; when sorting numerically, any non-numeric values are sent to the bottom of the list out of the way. To restore the data in the table to its original order just click the link that says 'none'.
TableSorter can cope with cells that span multiple columns of the table, and when sorting it will leave any column headers in place so that table remains legible.