I work for the Wireless Rehabilitation Engineering Research Center (RERC), a federally funded organization dedicated to promoting accessibility to wireless communications for people across the whole range of disabilities, both severe and moderate.

The issue of durability and toughness of wireless handsets is perhaps especially important for people with visual or motor function limitations (include the rapidly increasing numbers of elders in the developed world and elsewhere) who may have a greater likelihood of dropping things. Indeed, durability and toughness was identified as an important device feature by 62% of the respodents to our ongoing Survey of User Needs. It was the second most frequently identifed device feature after long battery life.

This concern with durability and toughness may become more pressing with the proliferation of touchscreen devices, though as OrangeCat noted above, any phone dropped onto the pavement from 2 feet will not look very good (I have direct evidence).

Anyway, details on our survey can be found at: http://www.wirelessrerc.org/for-consumers/survey-of-user-needs.html, and at our community site at: http://www.mywirelessreview.com/.