Well from that link I found they give specific info on what you can't do with bit fields:
The following restrictions apply to bit fields. You cannot:
Define an array of bit fields
Take the address of a bit field
Have a pointer to a bit field
Have a reference to a bit field
But that doesn't give me a feel for would be useful things I could do with bit fields. Anyone up to and able to show a simple, or useful, or at least something fun using a bit field structure?