Before the site's recent makeover, it used to list who was currently signed in. Now it has an icon next to your name of 2 people that lets them know you're online. Don't know what the difference is, if any tho and you have the option of disabling the little icon. Sometimes it's good to know that someone is actually here, in case you're trying to catch up with them, or you know they may read your post soon, but I don't think it's necessary for everyone to know which days I was here and which I wasn't. I don't think anyone really cares!
