Four dogs of various breeds and sizes sit at the feet of their owners, occasionally yipping at each other, at this crowded, artsy café. GREY DOG'S COFFEE takes canine friendliness very seriously, decorating with picket fences and dog statues and offering up remaining wall space to dog-loving artists. And the food is quite good, especially the oversized sandwiches. Although they sometimes take their dog conceit thing a little too far ("We deliver! Four legs are quicker than two!"), Grey Dog's got more atmosphere and just as much owner/pet-watching potential as any park's dog run.