I blogged on our dust storm last week. It was really bizarre to watch it rolling in on us. It was one of those things that you know intellectually is not really threatening but a steady diet of Stephen King and other authors had some part of my brain wondering if I shouldn't be driving north at 90MPH to stay ahead of it.
By the way, such storms are called a "haboob".
Radley Balko linked this time lapse video.