Have you been to the Hemingway House? That’s pretty interesting (especially if you enjoy the author) and plus you can see all the six-toed cats!
http://www.hemingwayhome.com/

There’s also a great restaurant that’s slightly off the beaten path called Pisces (?) I think. It used to be called Cafe Des Artistes. Anyway, the food is amazing and they have original Andy Warhol prints on the walls.

Here’s also a list of attractions from Lonely Planet’s website:
http://www.lonelyplanet.com/worldguide/usa/key-west/sights?ec_s_name=asc

And I also found the website for Pisces: http://www.pisceskeywest.com/
It’s definitely one of my all time favorite restaurants.

Lobstering, fishing and drinking. All are perfect way to spend a day in Key West.

@Kay Hemminway House is a great tour. I loved it!

@scamp: It’s such an awesome house with a great history! I really like how they let you hang out on the grounds for as long as you want after the tour. :)

The Audobon House is also great – it’s an old cottage with several original Audubon prints in it. I think it’s on the same street as the Hemingway house. We also took a tour of the Truman White House in the Truman Complex last time we were there, very pleasant. Another nice thing we did once was a small boat eco-tour to see dolphins. A sunset champagne cruise on a schooner was great; you get it on the pier in front of the Hilton. There’s a great French bakery on Duvall Street quite a ways down from the water. And Turtle Kraals is a nice pubby type place to eat at the marina….Oh – I want to go!

We love to stay at the Ocean Key House right at the end of Duvall. If you can get a room with a balcony overlooking Mallory Dock, you have a ringside seat for the Sunset Celebration. It is pricey though.