Jimmie Rodgers "Peach Pickin' Time in Georgia" contains the line "When the pickaninnies pick the cotton, I'll pick a wedding ring" I have usually substituted "cottonpickers" but once I slipped and performed the original in front of one of my darker friends - he only burst out laughing and took it as a reflection of the depth of our freindship that I felt comfortable enough to forget my usual edit. Intent and context are everything. Not what you say but how you say it. On the other hand some people I jammed with around Chicago would bring out a bluegrass tune called "Run, Nigger, Run" and sing it with gusto and bad intent.