First image, with no clouds:
(http://img402.imageshack.us/img402/3964/tgout0001.png)
Second with clouds, but not above the island (I used a painted shader). I put the default cumulus clouds, but I don't like them. I need to find some better:
(http://img541.imageshack.us/img541/3964/tgout0001.png)
Erwan