You may want to use several of the photos in publicity in the future. DO - Have a Polaroid camera handy at your table. Give it to them and sign and date the back of the picture. Suggest they use it for a book mark. This increases the odds that your book AND the picture will become more of a conversation piece.
Dove chocolates are another favorite.
Ask them if you can take the wrapper. . . You'll be glad you did. DO - If you are in town for a keynote or seminar, bring some seminar flyers to hand out. Invite the Community Relations person to attend your seminar for free. Suggest that they interview the book store manager or community relations person.