Re: What would be the properties of a photon at or near rest?

Light doesn't really travel more slowly in glass -- 
it only appears to. What light travels through space with matter 
in it, it interacts with the matter, and is "slowed down".  
A given photon is absorbed and re-emitted by an atom -- 
this is "scattering", and it takes some time to happen.

You could think of the analogy of playing "telephone" across a room.
Each person whispers into the next person's ear, who passes it on
to the next.  It takes a lot longer for your message to cross the room
than if you just shouted it out, but this doesn't mean that sound is
traveling more slowly.

Sometimes a photon will not be re-emitted, but the atom will "hold on"
to it, or it will dissipate it in the form of vibrations (heat).
In this case, you could say that the photon had come to "rest" -- 
it really disappears into another form of mass/energy.

Hope this helps,
Aaron