How well is your beer carbonating?

Some of my friends have asked how the Hefeweizen is doing. I told them its going well and I hope to have a taste in about 2 weeks.

One of the things many home brewers want to know is how to figure out if the beer is carbonating? I follow a simple process before capping the bottle: Usually there is a small gap between the opening of the bottle and the level of the beer in the bottle. I squeeze the PET bottle till the level of the liquid rises to the top of the bottle and then I cap. What I'm doing here is pushing all the air out of the bottle so that this space will be replaced by carbon dioxide produced during carbonation. Every few days or so, I squeeze the bottle and the harder it gets to squeeze the bottle, the better it is carbonating.

This can be done for PET bottles but not glass bottles. So what do you do when carbonating in glass bottles?

Here's something I plan to do: Whenever I use a glass bottle, I will fill a PET bottle with say half a litre of beer and see if the PET bottle is carbonating (by squeezing it every few days). If it is carbonating in the PET bottle, you can rest assured it is carbonating in the glass bottle too.