Song of the South was Disney's first (mostly) live-action film, and it is the only one not available on video in the US. The movie is controversial due to its depiction of African-Americans, though taken in the context of its time period, some people claim the controversy is unjustified. I've never actually seen the movie, and I don't go for bootleg copies of movies, so I can't comment on that aspect of things.
What I CAN comment about is the contribution of the movie to the Disney culture. EVERYONE, be it a Disneyholic or just someone who is familiar with Disney in general, knows the Zip-A-Dee-Doo-Dah song (which won a Best Song Oscar in 1948). Yes, it comes from this movie. The animated parts of Song of the South made it into many Disney compilation footage. And the movie inspired my all-time, far-above-all-others (slight pun intended) Disney World ride -- Splash Mountain.
WARNING: YOU WILL PROBABLY GET SOAKED!!! (But maybe less so if you sit in the back)
Splash Mountain is technically a flume ride, in the same way that Disney World is an amusement park. NOT. It is a celebration of the senses (hey, you'll even taste the water, trust me!) that happens while you sit in a "log" flume. Oh yeah, you will drop 52 ft at 40 mph at one point...But right before you do, you'll get an amazing view of the Magic Kingdom. Especially if you ride at night, when all the lights are on.
And while you're dropping, your picture will be taken. SMILE! (Really, not everyone screams in terror. I only did the first time.)
The ride tells the story of Brer Rabbit, an animated character from the movie. Brer Rabbit is a carefree rabbit with not a lot of sense, and we follow him as he goes about his carefree days and manages to annoy Brer Bear and Brer Fox, who then decide to hunt him. Right before you begin the climb for the big drop, we see poor Brer Rabbit was finally caught, and music of doom plays as you climb the big track...
The drop itself is actually long enough to be exhilarating but not terrifying, unless you suffer from motion sickness, in which case the whole ride is not recommended, since you're on water. After the drop we celebrate Brer Rabbit's miraculous escape from the silly creatures who hunted him. Watch for Brer Fox's tail being pulled by a determined crocodile...the whole ride is filled with colorful props and audio-animatronic critters, and you end up feeling like your face is going to split from grinning so much. It helps that the music is so excellent (all the songs are from the movie; the score was Oscar-nominated in 1948).
At the end of the ride, there is an area displaying the pictures of the plunging riders. Look for your picture, have the Cast Member in attendance write down its number for you if you like it, and you can purchase it in the inevitable gift shop on the way to the exit.
The ride is over 10 minutes long and tends to have obscenely long lines. Use a FastPass instead. Children have to be 40" tall to ride.
If you stand on the bridge to watch the flumes plunge, you may get wet. I actually like standing on the other side of the bridge, down a couple of stairs, where you can see the people floating after they plunge, and hear their comments. :)