Interesting thread.

Spiders definitely are not my choice of pet or for feeding.
As Ivory experienced, spiders can cause some pretty nasty damage through the process of a bite.

While I was in Japan I was bitten while sleeping and woke up with the right side of my body paralyzed and intense burning pain. Ended up with a nice size hole cut out of my thigh and a drain tube hanging out of it for a week.
We also had the occasional large poisonous centipede charging through the house so they also have been put on the I don't need list.