In their September 2011 issue, National Geographic posted an article about the top 10 literary cities in the world. You can read about recommended travel sites for writers, and about novels that were penned in and about those cities.
In Stockholm, Sweden (#6 on the list), travelers can visit the many places described in Stieg Larsson's popular book, The Girl With the Dragon Tattoo, as well as the statue dedicated to Pippi Longstocking author, Astrid Lindgren. On the way out, you can stop by City Hall to check out the location for the annual Nobel Prize dinners.
Number 9 is Melbourne, Australia. There you will find the 200-year-old State Library of Victoria, and exhibits in three galleries. In the back, visit the La Trobe Reading Room, a massive octagon-shaped space covered in engraved quotes by famous authors and classic thinkers. The weekly Saturday book market can be found in Fed Square, close to a bar called the Drunken Poet, where portraits of well-known authors hang on the walls.
If nothing else, stay the night at the Heathman Hotel in Portland, Oregon (#7) to get the "Books by Your Bedside" package. This includes a "personal tour of the lodging place's 2,000-volume library, made up entirely of signed books by author guests."
Read the full list of cities and sites here.