Sea-Bands (
http://www.sea-band.com/us/ ) are available over the counter at many/most pharmacies and stores with pharmacies (e.g.
WalMart, Target...) as well as from online retailors.
Sea-Bands DO have studies backing up their use:
http://www.sea-band.com/for-medical-professionals
I use Sea-Bands for nausea that is not caused by motion sickness on a regular basis, so using them for motion sickness was a no-brainer for me.
For my first cruise, I used a combination of Dramamine Less Drowsy (meclizine; same active ingredient as Bonine and the motion sicksness med they hand out on the ship for free, but there are no artificial sweetners (i.e. aspartame) in the Dramamine) and Sea-Bands. I also had original Dramamine/Gravol as a back-up, but since it makes me really drowsy I didn't want to take it unless I was desperate and I never got that desperate.
An important point about using Sea-Bands: it is very important that they are placed in the correct position. Their website has excellent info about how to do this.
I find sometimes if the placement is a bit off they dont work as well as usual or at all -- if I find myself wearing them and they are not working, I adjust their placement and it usually solves the problem.
Also, sometimes I find they do not get rid of 100% of nausea; sometimes they take it down a few notches to a level that is tolerable even if it may still not feel great -- e.g. from "i am going to imminently throw up, so don't mind me as I sit on the floor beside the toilet waiting for that to happen" (i.e. basically nearly incapacitated) down to "my stomach has disowned me and is telling me this, but I am just annoyed with it and so can carry on my day pretending the stomach still likes me" (i.e. annoying and it is still there, but it isn't limiting functioning; and, sometimes, it makes it go away completely

).
-SW