If your father is an avid reader, you can show him how much you care this Father's Day by getting a book. While the rise of the Kindle and the eBook are said to be the first step in making the printed page a thing of the past, many people still love the feeling of reading a real book. While you can find many books online (especially if copyright isn't an issue, as is usually the case for classic books), there's just something about holding a book in your hands, feeling its age and weight, that a downloaded file can never replicate.
The best site for buying used and new books is Abebooks.com, which cross-references thousands of used bookstores and specialty bookstores. Not only are used books cheap and a great nostalgia-item, but buying books used helps the environment!
While you might find the same items on eBay or Amazon, Abebooks also allows users to easily look for certain qualities in a book (for example, whether it is signed by the author). If your dad is an ardent fan of Dr. Seuss, for example, Abebooks can help you track down his more obscure works (like The Tough Coughs As He Ploughs The Dough or The Seven Lady Godivas), or even a copy of Green Eggs and Ham signed by the Good Doctor himself!
Even if you are not yourself a bibliophile, you will be amazed by the range of books available through Abebooks (usually at incredible prices, if the book is not especially rare or collectible). And if you feel like spending a lot on your old man this year, don't forget to check out their Most Expensive Sales list first. So go hit the books, and make this Father's Day a page-turner!