Bonine (Meclizine)-less drowsy than Dramamine (dimenhydrinate), but Dramamine works better for most. Be careful with Bonine, though...it made me MORE drowsy than Dramamine!
Ginger, in any form, has been proven to be effective in many studies. I like it crystallized, some like it in ginger ale or ginger beer, some like it in capsule form.
SeaBands (those brutal wrist straps) seem to work well for my DS, who gets pretty seasick, but like Kevin, I suspect the placebo effect on these.
TransdermScop works very well for many, but can be some serious side effects for the unlucky few. If you do get a prescription from your doctor for this, I'd try it out at home first.