It's pretty straightforward -
The forum homepage down at the bottom has a 'newest member' display. That sometimes changes but as Tom suggests most may be spambot type things.
To see who's been in just go to the link up top for 'Members List' and that gives you a list of all forum members whose accounts were fully activated. Gives you their name, join date, number of posts, avatars and also the date they were last logged in (there's some interesting reading there as well sometimes especially considering there aren't a whole lot of posters anymore) and info like that.
None of it is hidden. It's all information held by the site openly.
'If the Apocalypse starts, beep me!' - Buffy Summers
'The sky's the limit.....' Jean-Luc Picard, 'All Good Things'
courtesy of Saquist