I drive a 1995 Accord EX.
I noticed that when I back up, all I have to do is turn the steering wheel just a bit and it turns all the way by itself when I let go. Is this normal? If this is intentional, what is this feature called?

It's just an effect of the way the caster is set on cars. Just like the wheels on a shopping cart, when moving ahead they are stable and tend to keep the vehicle in a straight line, but in reverse they try to turn around, because of the way they trail the steering axis. This is called caster, it describes the tendency of the wheels when in motion, as set by caster angle.

Notice how in all those police videos where a car is in reverse without a driver, they're always going around in circles? That's why.

Thanks for the answer Jeff.
I just never noticed this phenomenon in other cars I have owned.
Now I'll go test it out on my motorcycle :)
-seth