Directly stolen from Brook Kohlheim's newsletter. "Good artists borrow, great artists steal." - Picasso
I'm a big fans of the 'horns' set, when not using 4-out, 1-in or two guard (Tony Hinkle style offense).
This combines the richness of the horns environment with the nastiness of the Flex (screen-the-screener, set one-get one approach).