Last trip i remember struggling because i wanted to wear my watch and my MB on the same arm. I was thinking this trip i might switch my MB to the other wrist, but was curious if anybody knows whether the parks and rides are set up this way. Obviously, i can use whichever arm i want, but are all of the Mickey heads to touch the band to on the left side, which would make it inconvenient...? Cant remember....
All the rides have two Fast Pass touch points, one on the left, one on the right, and they are always asking people to use both. You can use either arm on the touch point easily regardless of where your MB is.
At the park entrance, you stand more or less in front of the touch points. The only time the arm you wear your MB on really matters is at the park entrance, if you are wearing your MB on the arm that has the finger you scanned, it can be a little awkward, but it's not a big deal.
I usually wear my MB on my right arm, even though I feel like I should wear it on my left, only because I wear a fit bit on my left arm. I've had several Photopass photographers tell me that sometimes the photopass scanner has a hard time scanning the MB because the fit bit can interfere with it. I don't know if it's true or not, but that's what I was told.
If you don't want to wear the MB on your arm, you can get one of the keychain or lanyard accessories (they cost about $10) and move the mickey head puck from the MB to the keychain or lanyard. Or of course, you can choose to just put your MB on a bag, in your pocket, on a belt loop, or whatever.