What kind of spider has the body style of of black widow but does not have the red hourglass and is more of a brown color than the jet black color of a Black widow Is it dangerous?

Spiders of the genus 'Steatoda' are often mistaken for Black widow spiders , and are known as false black widows; however Steatoda are significantly less harmful to humans. Steatoda are shaped similarly to widow spiders, with round, bulbous abdomens. A few come in very, very dark brown and closely resemble the black widow. To be safe I recommend following the link I added at the bottom and looking at the pictures and information, it might help you narrow down exactly what spider your talking about. Also knowing what part of the world you are in would help with the identification.

http://en.wikipedia.org/wiki/False_widow_spider