This may be a fun idea for engagement party - have everyone leave a message regarding their special skills or what they would like to help with. Maybe there are things you dont know you can ask your bridal party to help with!
Pinata Guest book - I ordered one in pink that's a heart with silver trim. They are cutting a slot so the guests can put their papers inside and we will open on christmas eve (I can't wait a whole year!) : )
We could have a marriage advice, message in a bottle set up where guests can write on pieces of paper and put it in the bottle for us to open later. I have some large vases and we would just need sand, rope or twine, and some message paper.