I'm glad to see you made the multi-column sort key configurable. My instinct was to use the [CTRL] key, not the [SHIFT] key (although I know Outlook uses the [SHIFT] key.)
Tablesorter can be configured to use either SHIFT or CTRL, all though SHIFT is default. Here is a example on how to change it to the control key: $("table").tablesorter({ sorting: { // valid values: ctrlKey, altKey, shiftKey multisortKey: 'ctrlKey', } }); /christian