Dont know if someone has posted this here before, but I hadn't seen it and wanted to make sure you guys knew about this resource. I found a link to a set of 240 sky boxes which are free to use (some conditions may apply however that is noted in the download). So for any of you searching for that perfect sky box, THIS is where you will find it. It is basically a compilation of EVERY SINGLE free sky box ever created, all 240 of them. Some of them are really low res, but some of them are quite high resolution. there is basically a sky box for every situation.
The file is about 465 MB
To read a description of the file and what it contains, go here: http://lvlworld.com/review.php?id=2023
Download the file Here: http://lvlworld.com/dl.php?id=2023&ftp=lvl&zip=q3sky
Also, I will soon post a link to download a split rar which will be hosted on my mediafire site, in case the link above fails. When the upload is complete, i will post details on how to open the file set.