Quote fromI've been irritated by these clouds ever since i've seen them, but never though about making a client mod.
The updated version is available here.
(I seem to be unable to post anything in opera? it just takes me back to the forum posts, without actually posting anything?)
Zaraza107 has been updating this for a few versions now http://www.minecraftforum.net/viewtopic.php?f=25&t=88885