Decisions are easy at Flo's in Cape Neddick. Hot dogs are the only thing offered, and you only have to know how many you want. The three-bite wonders come with Flo's fabulous hot sauce-a spicy-sweet onion relish-and your choice of mayo or mustard. Those with hearty appetites will find half a dozen about right, although some are known to order a few more for the road. When the six counter stools are taken (usually), there are picnic tables outside.