Working for the marketing department of a local newspaper I had a great honor bestowed upon me: the keys to the prize room. The prize room is just what it sounds like--a place where they keep prizes of every shape and size emblazoned with the paper's name. Sure there are the expected pens and notepads but there are also golf towels, camping chairs, lunch cans, computer gadgets and more.
Many authors also have a "prize room". Sadly it usually contains just two things: copies of their books and bookmarks. There are only two problems with these prize rooms. First, giving away copies of your book can get expensive. Second, everyone has countless bookmarks and, unless they collect bookmarks like I do, they have a good chance of ending up in the garbage. So what's an author to do? Branch out!
As a WOW blog tour organizer and a book reviewer, I've seen authors give away many different things. Not only does it often help their budget but it keeps readers interested in their blog tours or live appearances. They came to the first blog to read about your book and enter to win the book but they follow you to other blogs hoping to win those other, quirky prizes.
There are companies that will plaster your name, the title of your book, and your website on just about anything. Recently I saw tattoos of a book character! Of course, the non-permanent washable type. My advice is to watch for sales and choose a "prize" that is somehow related to your book. Recently I saw big red plastic stirring spoons...great for a cookbook or a book called The Big Spoon, not great for a book about Victorian England or how to crochet.
You can also go the sort-of-homemade route which can give you that original prize everyone will talk about--and by extension they'll talk about your book! One author of a novel with gardeners as main characters gave away seed packets (very inexpensive!) . That same author, Mindy Friddle, also recreated the cover of her novel with old boots and plants from her garden for live appearances. Another gave away a recipe (all printed up on an index-sized card and ready to slide into someone's recipe book). And a third gave away a CD of big band music because her novel took place during World War II.
Use your imagination and choose a giveaway that is memorable and gives recipients all the vital stats of your book: title, author, website, and a one sentence synopsis if you can manage it.