Websites
Complete with photos, quotes, a bibliography, and links to other sites.
A brief overview of the Disney attraction.
The website to for the Mark Twain Cave and Campground. Here you can check out pictures of the cave in Twain's hometown of Hannibal, Missouri. Tom Sawyer's cave is based off of this one.
Movie or TV Productions
An old film adaptation of Twain's novel. This was the fourth film based on the novel, but the first one in color.
This musical includes a young Jodie Foster as Becky.
Starring Jonathan Taylor Thomas as Tom and Brad Renfro as Huck.
In which Tom is a member of the American Secret Service. (Don't look for him in the comic book, though. He was added in order to appeal to American audiences.)
Documents
Project Gutenberg offer the full text of The Adventures of Tom Sawyer for free online. This e-text edition even includes illustrations.
Here's a TIME magazine article on psychoanalysis and cures for warts. It references Tom and Huck's spunk-water and dead cat cure.
Video
Watch them rocking out.
Watch the full 1938 film on YouTube.