http://youarelistening.to/ streams a hypnotising mix of police department radio over ambient electronica.

You can control the levels and when you get it just so you'll have the perfect soundtrack for composing your post-apocalyptic retro-romantic dreamscapes. You do write those, right?

If LA doesn't do it for you try Montreal.

(Sadly Sydney and NSW Police don't make the options, but I reckon a mix of Blue Murder dialogue over B(if)tek noodlings is a fairly compelling imaginary place to go.)