Fictitious street names

You can use actual street names. If you give a street number, then it is a good idea for it to be a number that is not in used, parking lot locations, etc.

As for Paris, Eco used actual streets and locations in Foucault's Pendulum.

You can make up your own fictitious street names, of course!

For real streets in Paris, there's always: http://maps.google.com/maps?hl=en&ie=UTF8&ll=48.855652,2.355409&spn=0.013356,0.038581&z=15