One who is involved in the scene community, but could not be classified as a scenester. Usually has some scenester friends. Somehow associated with the community (example: frequents scene parties or shows), but is obviously not a scenester.
The main distinguishing factor between halfsters and scenesters is lack of image consciousness and acceptance of non-scene culture.
The main distinguishing factor between halfsters and nonsters (those unrelated to the scene community) is acceptance of the scene community and slight involvement in the community. Nonsters do not have scenester friends (okay, they might have one or two scenester friends, but that's generally it) and are not involved in the community.

(noun) A successful type of theft which results in an acceptable, impressive and rewarding payday for the protagonist.