Actually all spiders are venomous to some extent (not poisonous).
True, and even here the very large ones that you can find in garages and stuff can give a bite that causes irritation to human skin. But mostly their venom is only deadly to other bugs.
Last summer there was a spider outside my window and a wasp flew into its web. The spider jumped on the wasp's back at the same moment the wasp got loose. There was a brief struggle and then the wasp flew away with the spider still on its back. I have no idea who won the battle, but it made me think of a rodeo.
They really do the funniest things.
@Shabbychicdee - I have to be honest, I have no time for people who are all pro-animal but are happy to kill bugs. If you care about living things, you should care about all of them. You can't just save the ones you personally think are 'cute'. (I also have similar feelings when I see a 'save the animals' poster nailed to a tree.)