you should check out the guests, Soph. just click on them. it shows you if they are old members or whatnot. i'm curious with guests, it sucks i can't check them out too.
i've done that on a few i've seen lurking in certain threads
and i've been right with my guesses a few time
i do the same thing on zomg
i hate when i see an IP i don't know, on all the time. it gets me paranoid about who it is that's obsessively lurking lol