I made one with some sage and rosemary in it, and those babies think they OWN the place! Still, it's a nice feature, and the anti-neighbourhood meltdown syndrome is important - not for the neighbours, but for my wife! She's a townie, and likes plain grass (boring). Anyway, here's the result (in the middle of that mess):
Got some nice bronze and green fennels going in there, a mass of perennial rocket and lemon-balm and oregano too.