A recent mini-project of mine was to create clouds in Maya. I achieved it by creating a fluids container and toggling with the textures and shading attributes.
I also created a sky using Mental Ray's image-based-lighting.
I then used the expression fluidShape1.textureOriginZ=time*.02 to animate the clouds.
I rendered the sequence as .JPGs and then composited them in After Effects.
This was a small interactive exercise which I created in flash. I designed all of the elements in Adobe Flash and coded it in the ActionScript programming language. Hover and click on the buildings!
Here is the link to the source page in case the html embedding does not work.
The song is a Butch Clancy dubstep cover of Foster the People's "Pumped Up Kicks".