One of my friends had the greatest personalized gift idea for her sister who got married this past weekend. A month before the wedding she emailed all of the invited guests and asked them to email in a recipe and picture. Some of the guests sent pictures of the food, others sent pictures of themselves. My friend took all of the recipes, put them in documents, added borders and printed them. She bought a 8 by 11 scrapbook and put each sheet in to the page protectors and created the best cookbook a bride could ask for.
One suggestion would be that if you dont want the project to be enormous you could invite just the wedding party or immediate family to contribute. I also love that all of the recipes were typed so they will be easy to read. Much better then when everyone writes a recipe card for you.