The A-Line Bob got its name from the shape it makes around its wearer's face---think of a long, straight bang as the cross-line of an A. Make sense? To get this hot look, you should pair a straight bang with blunt hair frames. It can either be very hot (think Catherine Zeta Jones in Chicago), or terribly, terribly wrong. I think Saleisha's awful haircut was a major factor in why so many people had problems with her victory on America's Next Top Model Season 9.
The A-line bob haircut is an edgy hairstyle with very straight lines. It looks best on people with strong facial features who have time to put a little styling effort into their hair. See pictures and articles about A-line bobs here.