Since everyone is on the subject of clouds most recently, I figured I throw in a few of my own.  They're not  as great as some of the others posted.  I was at 5,500' MSL when I snapped the aerial photos.

Practicing an engine shutdown and securing procedures while looking at distant thunderstorms.
     

On the leading edge of the thunderstorms outside the final approach fix (yeah, ATC vectored me through the leading edge of that crap).


After we landed, this P-3 takes off into the weather.
     

Shortly behind the P-3, a NASA T-38 Talon departs.


Clouds and wind as the storm rolls in.

Wow! Great catch with the lightning! Like the NASA T-38 too!

Ohh, I like the one from your backyard, gives Kris some competition!