How to park a bike in the city centre?

The city centre of Oxford isn't exactly heaven on earth for car drivers. With the roadworks near Highstreet, loads of one-way streets and the pedestrians zones near Cornmarket it takes ages to travel by car in downtown Oxford. The City Council encourages citizens and tourists not to travel by car and I do think that's a good thing. It suits an old city full of history like Oxford not to have too much car traffic in the town centre. A lot of residents, especially students and people who work at the University, use their bikes which leads to another problem; where do you park your bike? Last week I saw this bike near the Radcliffe Camera, attached in a rather unusual way, I would say.