ok.. you can check some of my spiders at
http://pets.binary-pulse.co.uk
i've had spiders for coming close to a year and half now, and i have yet to be bitten.
Certain species i'll handle no problem, others i wont.
one i wont is 'kumo', my cobalt blue, it bites at ANYTHING.
my tarantulas vary in age (and therefore size)
my biggest is almost 6 inches legspan (when relaxed) and have fangs approximagelt 1/2 to 3/4 of an inch long, and my smallest can sit on a 5 pence piece (but will grow to 5 inches at least)
my favorites are the tree dwellers but these are almost impossible to handle because they're very fast and can take running jumps.
they're not 'intelligent' per say, but they do reason what they attack.. they know i'm nota cricket, because i dont vibrate the floor like a cricket would, so they would much much rather run away from me than bite me (except kumo)
one of my spiders (hayden) has worked out how to slide the glass open on tis terrarium, and does so without fail - so we've gaffer taped it shut - so they do have an iota of intelligence (i guess)..
a common misconception is that if you get bitten by a tarantula you've got 4 minutes to get to a hospital or die!.
the one on my hand above would be no worse than a couple of bee stings in terms of irritation and pain etc.
the cobalt blue seen above would be a bit worse (slightly more potent venom and a more violent bite)
only chance of my dying is if i'm allergic to their venom and go into anaphylactic shock - but here's to hoping!.