See that? It's lint from my husband's front-shirt pocket. Lint that got pushed into the seams flanking the Dell Streak's display when I brushed it off the face of the device.
I got it all out with a quick burst of compressed air, but I can see how a couple of particles of dust and other debris could get in there unnoticed and really accumulate and get pretty disgusting-looking over time. It's too bad that the Gorilla Glass used for the display couldn't have been placed over the entire front of the Streak to make it completely seamless. That would've been very nice.