A few nights ago I had a few hours to go on a bit-torrent download, and didn’t really want to leave it uncapped over night. But at the same time didn’t want to rate limit the uploading while still downloading (there were only a few people get the file and the only seed was really slow).
In my moment of need, I found µTorrent already had the feature I wanted, but had never seen prior Alternate upload rate when not downloading. I set it to a lousy 2kb which helped me sleep better that night.