After my few and far between years of attending and being in weddings, I have only been a bridesmaid once, helped my father videotape about twenty times and while all those are important I have some to realize the best spot ever is to guard the guestbook.
Think about it, if you're a bridesmaid you have to get a dress (and depending upon the bride it could be really hideous and make you look like a credenza), you have to get special shoes/jewelry, you have to go to the scary hassle of getting all that fitted (I have a deep fear of shoe shopping), according to the new tradition if the bride so demands it you must appease her every whim including addressing invitations to people you don't know and help to trap the groom should he make a runner (here's how to throw a lasso).
But if you're in charge of the guestbook, you just have to get dressed up a bit (still not fun), show up about 30 minutes before the thing starts (as opposed to hours before to get your hair and makeup done), sit in a chair collecting gifts and cards, and if you get bored write in fun names like "Brad Pitt" into the guest book. It really helps that it's one of the least important jobs, essentially an open book and a pen could do it. So if you wanted to slack off, no one would care either.
And you still get all the perks of being in the bridal party, free food at the rehersal dinner, your name in the program, people asking you where the bathroom is.
That's why I told all my friends that if I have to be in anymore wedding I call guestbook. I still have a few openings in June if anyone else requires my services.