Hey....from the Canadian East coast perspective....
Art and I wanted to keep our wedding party small and even (ie. we wanted even numbers of girls and guys) Art doesn't have a lot of friends, while I have tons! If I could, I would have had all my sisters standing with me (now that would have been a HUGE wedding party!) But, things like that get very expensive, quickly.
We ended up with 3 on each side. I had one of my sisters as a bridesmaid (she was the one who called me to give me a bid and has been such a great friend and sister ever since...she is one of my best friends now!)
I had one of my sorority sisters do a reading during the ceremony, 2 hand out programs and bubbles before the ceremony, and 2 take polaroids for my guestbook (we had a photo book where guests signed their best wishes next to a pic of them!

) ALL of them felt very honored to be included in even this small way in my wedding.
From the time I started planning, all my sisters wanted to help wherever they could. While I wish I could have included all of them in some way, I chose the ones closest to me to help out. I gave each of them a wrist corasage of yellow roses (our sorority flower) to acknowledge their help....and sat them at a table of honored guests at the front of the reception...and thanked each of them in my programs. I also included my sorority in a small way by having a yellow rose (our flower) in the center of my cascading purple and white rose bouquet (my bridesmaid/sorority sister also had a yellow rose). Everyone asked about the rose in the center...and I responded saying "This is a small way of including all my sisters in my wedding day...they are a big part of my life and I wanted to show my sisterly love"
I guess what I'm trying to say is that I know my sisters who helped me out felt it was an honor and not a burden or something wrong that I had asked them to "help" me out on my wedding day!