Buttons on feet of X220i

[djstanton]

I just bought my X220i and I have a question about the rubber feet. On the two feet closest to the front of the laptop there seem to be buttons. They seem to be depressed when the laptop is resting on a surface and extended when you pick the laptop up. I found one post off site that referred to them as "nipples" and that they were actually airbags. Other than that I can find no documentation about them. To me they appear to be contact buttons of some sort.

Does anybody know if these are indeed buttons and if so what do they do?

[ThinkRob]

The nubs that you're referring to function as shock absorbers to help reduce the impact force from setting down the laptop too hard.