Bun or Bob?

My hair has reached, once again, the point where no reasonable amount of conditioner will prevent knotting. (This time it has reached this point while still looking decent, usually the last 2 inches of hair are just raggedy split ends.) This means that by the end of the day I want to shave my head. So my choices are:

• Get a couple inches off (possibly making my hair the really annoying length)
• Get a bob, just long enough to tuck behind the ear (yes I want to get my hair cut just as the weather starts to make long hair bearable again)
• Wear my hair in a bun everyday (ponytails don't cut it)
  

What are your suggestions?