Want To Find Your Phone? Just Google It
http://goo.gl/A9mTSN
Type "find my phone" into Google, and provided you're logged into your browser with the same Google account as your phone, you'll instantly get a map of its location, along with the option to ring it.
To get at more serious settings — like the option to wipe your phone, before anyone can Facebook those nudes — you'll still need Android Device Manager installed. But if you've lost your phone down the back of the couch (or had a particularly immemorable night out), a Google browser is all you need from now on.