I've looked at clouds from both side now...

[paulselhi]

Joni Mitchell ?

Just experimenting with particles for clouds and some messing around with motion blur:

Avengers 13.8 kb (http://www.black-and-white-to-color.com/stuff/av1.jpg)

I suppose i could animate this if i had half an excuse :D

[YvetteKuhns]

Looks nice. The plane in the background seems gray and almost ghost-like. The plane in the foreground is very black and the lighting isn't bright like the sky appears to be. The clouds look good.