share field across content types

Hi

I'm not sure if I'm missing something obvious in Drupal 7 but is there a way to share, synchronise and update/edit a field within a content type?

I have two content types that require the same field which relates to 'project status' (this would include statuses such as 'provision', 'live', 'cancelled' etc but in fact around 20+ statuses). Each content types must have the same status and thus be synchronised so any change in one must be reflected in the other.

Is there a way of doing this.