Can I see who is lurking while logged off?

[styleforum]

Haha, you don't have to care, but I thought it would be nice. Sometimes people log off to lurk/stalk/be creepy to people, so I was wondering if there was a way to track that.

I guess I (well someone) could write a job that would, every 1/2hr or whatever, compare guest IPs to known user IPs and tell you the ones who have recently browsed while logged out. That would cut the load down a lot and accomplish basically what I want to know.