Build your own Universal Multi Dial Solar Time Device.
Make your own customized paper sundial. This website creates a PDF based on your location so that you can easily print out and make a paper sundial.
The National Maritime Museum, Greenwich has some excellent online collections related to maritime history and technology, including telescopes, marine chronometers, sundials, and a whole lot more. Some stuff I've been looking at: John Harrison's chronometers (described in Dava Sobel's book Longitude), polyhedral sundials, and pocket globes.