After using pills, patches, seabands, ginger etc, I splurged and bought a Relief Band (which I read about on this website). They are pricy but we have found it very effective. After riding Expedition Everest and Mission Space and feeling very dizzy, put on the band and felt back to normal after about 5 minutes. Maybe it is in my head, but if it is it is worth it!
http://www.amazon.com/Electronic-Relief-Band-Motion-Sickness/dp/B0000AY4VL
http://www.amazon.com/Electronic-Relief-Band-Motion-Sickness/dp/B0000AY4VL