Proximity sensor for around 1inch and glass

I'm trying to find a proximity sensor that will work to detect an object that comes within about an inch or two and can also work if its glass.

I was checking out this site: http://bildr.org/2011/03/various-proximity-sensors-arduino/
The other 2 looks like it would not work so well since its very close proximity. I just need to check if a cup or glass is placed in front of a spout.

The QRD1114 IR emitted / Phototransistor looks like it would be good for the distance but is using IR. Would that work with glasses, like glass cups?

Are there other sensors I should be looking at?

I expect that the glass will reflect enough to be sensed but I am not sure. You can get the QRD1114 for well under $3 so you should probably just give it a try.