I am the father of a 25 year old bride-to-be, who is getting married in the fall of 2007. She has chosen to walk down the aisle alone. This scenario seems very weird to me. I know that day will be hers and I wouldn't want to spoil it in any way. Is this a common custom? Am I overreacting?

Yes it is very common, I would say 90 percent of the weddings I do the bride walks alone, the father is sitting on the front pew and merely walks up to join his daughter after she gets up to the front

Does she have a steph father too?

For some more (dare I say?) "modern" women, the idea of being given away is too reflective of being handled as the property they once actually were. So that whole part of the ceremony is left out. I was like this and explained to my dad so that no hurt feelings occurred. I think he disapproved but he was like that about many aspects of my life. It was also helped out by the fact that my dad was not paying for the wedding either--we paid for it ourselves. I was happy to invite him as a guest like anyone else in my family.