Barcelona in September!!!
Foto Ruta is a lot of fun, depedning on your existing photo skills. A lot fo what they teach is rather rudimentary but good to know, and their phone photography tour addresses a lot of what make phone fotos awful. Runner Bean IS a bit touristy, but if you want to see the sights, then you're a tourist. We're biased, but think a good guidebook might give you more, but you can't beat the touch and feel of a real guide.
As for seeing Gaudi's architecture, look into the whole Modenisme movement. Buy the Ruta de Modernisme guide (12€) at any bookstore or the tourist office under Placa de Catalunya. Along with the guide, it contains coupons with up to 50 percent on entrance fees to the Modernista buildings. The guide itself and its accompanying map make invaluable (if sometimes too highly detailed) references to 116 Modernista sites around the city.
Have a great time!