PCD and their whole image and concept is ripped off from the girl group "vanity 6" that Prince put together and wrote and produced all the songs for in the early 80's.
PCD's Nicole looks JUST like V6's lead singer Vanity as well.
Nicole PCD (2005):
Vanity (Vanity 6) (1982):
oh, and 'don't cha' is a complete rip off of Prince's production as well. The drum pattern is very similar to "when doves cry".