Wirelessly posted (BlackBerry7130/4.1.0 Profile/MIDP-2.0 Configuration/CLDC-1.1 VendorID/102)

Dust is a fact of life with cell phones. While I too world like a dust free phone there are only a few with sealed displays. I have several BB's & find in general that they are fairly dust resistant. While I am very careful with mine I still put them in my pocket which is a bad practice [pocket lint] & yet after 9 months my 7130c has no dust under the display.
Then there is another way to look at it, while we are concerned about dust, the windows mobile users devices are freezing & crashing! So it could be a lot worse.
Finally it's important to remember there is no perfect phone. So from my perspective I'm very happy with my BlackBerry's.

Via: 7130c