[quote=@Mahz]
Hmm, this is a decent idea. But I think we'd have to dig in to what invisibility-mode is for and what people are trying to get out of it when they use it.

The invisibility system, as far as I can tell, is really just intended for temporary privacy. Like when you tell someone you can't reply to a roleplay tonight because you're going to bed but you get on in an hour to PM your main squeeze and want to avoid the awkward "I thought you were going to bed..." confrontation.

Until someone corrects me, it seems like permanent invisibility-mode is an anti-feature. Maybe it shouldn't be something you just set and forget for eternity.[/quote]
I think that's mostly it when you mention how people that want to stay hidden may just want to come and read RPs or PM people. Your regular member is going to guess the approximate time when someone is generally on anyways (being in the US, Australasia, or Europe). I think the term "Lurking" is better at explaining it than Invisible. I do like [@Ellri]'s idea that when someone is a lurker they will state that they have been online sometime during the last 24hrs, 1 week, etc. You can see the person is an active forum member but won't see when they're on exactly.