Thanks for the feedback, everyone. Interestingly, I read the opposite advice on other sites (to use them for presses rather than pulls so your weak grip doesn't interfere with your workout). I'll use them for curls and rows for now, and see how it goes.
"Don't go in there, General, it's a trap! That's a grain chamber. It makes people like you into people like me."
Sorry, I don't see what all the hand-wringing is about when it comes to presses. If anything, there's less stress on your grip than with, say, a deadlift. The damned bar would have to magically fall out of the grip and pass through your hand. Physics is your friend.
I use the Fat Gripz to do additional sets with lighter weights of certain exercises than I can do with them. So if I'm deadlifting, I'll do additional sets with the Fat Gripz after my heavy sets. You can't just toss them on your working weights and expect to be able to still execute the lift.
My favorite lifts to do with them are: Farmer's Walk, deadlifts (or 1 deadlift and then a hang), pullups (they fit nicely on some doorway bars), and bicep curls.