I like this tool.  GABBI is--according to their web page--"...a free web utility that allows you to create and save a backgammon board
diagram. You can create the board manually and/or import/export to or from gnubg."

GABBI--Generate A Backgammon Board Interactively

Nice for creating board positions from my crazy games that I can then paste into emails for my pals!

(If you've got your own favorite utilities, please let me know.)