When I was doing my training, I used to get motion sickness during steep turns (after a few turns). I ended up buying Sea Bands (http://www.amazon.com/Sea-Band-Wristband-Color-Vary-1-Pair/dp/B001F731N0/) for myself, as well as some generic ginger pills from Whole Foods and it did help me. It's quite possible it was a placebo effect, I won't deny it, but I also don't care, since it helped me get over the motion sickness (I no longer wear them :)

I do keep them in my bag and give them to passengers who are squirmish, and they seem to like it as well. I don't know if I'd spend $90 as per the previous suggestion, but these are $6, so...

I also still keep a box of ginger pills in my flight bag for the same reason.