You can creat a decent mirror type effect just using a blinn shader and raytracing, i need to try out vladimirjp's method as well though.

Try these settings for a start. Create a blinn, in the attribute editor turn transparency all the way up, leave all the common settings at default. Open up the Raytracing options and enable Refractions. Refractive Index 1.3, reflection limit 5 and reflection specularity to around .2.

In the reder globals, enable raytracing, set Reflections, refractions and shadows all to 10. Try a render.

Might not be perfect for your scene but you can fiddle with the settings until it suits your need more.