Some remarkable dust devil movies have just come down from Spirit. Exploratorium currently isn't updating, so with Midnight Mars Browser you'll need to download the raw images from JPL using the "Update Images from JPL" or "Advanced Update from JPL" menu options.
Also, these movies are so exciting that JPL has posted their own processed versions almost immediately:
Gusev Dust Devil Movie, Sol 456 (Plain and Isolated)
Gusev Dust Devil Movie, Sol 459 (Plain and Isolated)
Gusev Dust Devil Movie, Sol 456 (Enhanced)
Gusev Dust Devil Movie, Sol 459 (Enhanced)
See also the "Live Dust Devil" discussion thread on Unmanned Spaceflight.
To view the sequences of images in MMB, use the following information to find the images, then step through then using the left and right arrow keys:
"First, one in the extreme distance (practically on the horizon), starting at 2\n\455\2N166754107ESFA9C2P1560L0M1.JPG and lasting for 21 frames (it doesn't really become visible until the 5th frame or so)
Then, one extremely close, visible starting at 2\n\456\2N166841509ESFA9DWP1560L0M1.JPG and visible for 2 frames
Then, a lovely one starting at 2\n\459\2N167103718ESFA9F4P1560L0M1.JPG in the mid-distance, a 9-frame sequence
Then, *several* caught in a 10-frame pancam sequence starting at 2\p\461\2P167292304ESFA9GEP2888L2M1.JPG"
Update: See also this discussion thread no Nirgal's colorized versions of the enhanced dust devil images.
Update: As soon as I have time, I've really got to add a movie-generation feature to MMB.