Since I started this thread I've decided to change the setting of a sci fi story I was writing from the far future to the preset/near-future. As a general rule, I believe simplicity in storytelling is best--if the function of two characters can be filled by one, cut one of them, for example ( I do that a lot).
In this case I realized the story didn't need futuristic technology; I just wanted to create an alternate world where slavery was accepted. Writing about is most familiar to you is best, and I don't feel like inventing a bunch of new gadgets if they don't affect the plot.
That slaves just a few years from now could have tracking devices in their collars, be prevented from getting pregnant, or have their sexual orientation altered, doesn't require too much suspension of disbelief, does it?