One of Ashley's bridesmaids couldn't make it to the wedding due to health issues, so she was virtually walked down the aisle via Skype! There is no reason in this wild technological age that webcams can't bring us all together.
Here's what Ashley said:
We decided to not let distance stand in the way, and set up a wireless router so that she could be with us via Skype. We had one of the groomsmen carry a laptop with my bridesmaid down the aisle and put her on a small stand with the other attendants.
Naturally, you can use this trick for wedding guests too, like Scott's mom and stepdad "sitting" in the front row: