Originally Posted by TexasDreams

There IS actually a hack for vBulletin that does just that. I've thought about putting that in for GFY, but I haven't included it as of yet because it might depress some users.

Total Time Spent On Board
Author: tnguy3n

This hack shows total time that users spent on the board.

To show all time units including seconds, minutes, hours, etc, uncomment lines for thoese variables in "Total Spent Time On Board" plugin.