Edible favors are a great idea, and almost all of these favors could be accented with personalized bookmarks too. Or even unpersonalized; print a nice wedding-related poem on one side and details about the type of edible favor on the back side.

After the food part of the favor is gone, the guests will still have the bookmarks left to use in their cookbooks or put on their refrigerators so they always know where they can get or make more of those favors for themselves.