sorting by time online

Within groups it is possible to sort by time the computer was “last online” if is it currently offline.  I would like to request that another column be created called “online since” so we can sort by how long the computers have been online.  The data is already in your database.  You can see it by looking at the properties of any computer.  It would be helpful for many different reasons.  I have seen where other people have requested this same thing.