Well, I don't really try to "sneak" mine in because they are legally allowed to go anywhere I go since they are service dogs, but I also try not to make it a big deal so I am discreet. If anyone says anything to me I simply inform them that they are service animals and that is usually all it takes for them to leave us alone.
I have had occasions however, one was a restaurant in Santa Barbara, where we tried to sit outside but the host sat other people there who arrived after us, and they were not going to allow us to go inside until I asked to speak to the manager and gave him a copy of the Service Animals in Businesses FAQ sheet (which I try to have w.me at all times) put out by the US Justice Dept. We were then promptly seated.
I was also asked to leave a See's Candy Store and I didn't have the FAQ sheet but I simply told the 2 employees who complained that my dog was legally allowed to be there as a service animal. I made my ourchase and left.
I use a dog stroller too which is great for transport!!
