What is it about Apple computers that generates such a cult following?

I know people who just have to buy the newest thing from Apple.
They buy the newest iTouch when they already have the newest iPhone. I know a guy who bought every iPod that ever came out. When a new one comes out, he throws away the old one.
Yes, in the trash. This sort of fanatical behavior is an obsession with people. Now we have people waiting in line all night buying mulitple iPads and all we all know that not all of these people buying multiple pads are selling them on eBay later. So why are people so willing to marrying themselves to a brand?