Another Way to find Dust on your Sensor

Looking back over some google+ photo autoawesomes, of my autobacked up photos. Ok you got me, I do eventually look through them. I noticed that some dust particles I had missed in my sensor cleaning where really highlighted in any HDR images. I assume that this is because the detail of dust is strongest on the slightly over exposed image from the bracketed set, and the google+ hdr process is trying to preserve that detail. This is really an abstract and secondary way to check for dust I still recommend taking a direct image of the sky as a quicker and easier way to detect dust.