i have a spider that is black with a white strip on its back?
black and white jumping spider
It might be a half albino black widow
A common garden spider, which are completely harmless.
It's probably the violin spider. That's just a guess.
Well a black widow is black with a red shape on it's back but no gray. I dont know if that was the answer you were looking for.
Argiope aurantia, or the black and yellow garden spider, lives in California and has two yellow stripes running lengthwise down its back. They are not dangerous to humans.
daring jumping spider
orb weaver spider.
crab spider..won't hurt you
Probably, it's an Araneus diadematus; see link below.
Its the Bold Jumping Spider or Daring Jumping Spider.
It sounds like a Funnel Web Spider or just a common House Spider.
The spider that is black with a white crescent on its back is the Brown House Spider. This spider is often confused with the red-back spider.
There is a spider that is black and white. It is also kind of fluzzy looking. It is a Regal Jumping Spider. There are non venomous.
Black and Yellow Garden Spider http://www.enature.com/fieldguides/detail.asp?recNum=IS0107
The kind of spider that is large 3 inches black and fuzzy with white stripes and found in the Bahamas is a tarantula. These tend to hide most of the time, but they may come out when it rains or if they are disturbed.
I believe that is part of the Black Widow family.