IDK what this would go but.... Is there a bukkit plug-in to keep track of total time online? Also one to kick a player if they go AFK after X mins?
I know various plugins that do other things such as LogBlock have this funtion, however for just the online time a quick search of plugins reveals that this one called CrazyOnline may do what you want, check it out at: http://dev.bukkit.org/server-mods/crazyonline/
Mind though, you posted this in the wrong section. There's a plugin request forum. But as you already have your answers.. I recommend not taking Essentials though.
You will find what you are looking for with OnTime (... Wrt the time tracking not the afk kick) http://dev.bukkit.org/server-mods/ontime/
If you are looking for total time go for Loyalty Points. It shows your time when you type /lp playtime and there's a point tracking system which can be edited in the config.