It’s easy. Simply throw “-o Acquire::http::Dl-Limit=X” in your apt-get command where X is the kb/s you wish to limit it to. So for example let’s say that you want to limit an apt-get upgrade command to roughly 50kb/s of bandwidth. Simply issue the following command:
sudo apt-get -o Acquire::http::Dl-Limit=50 upgrade
Previously I was running KDE 4.3.3 on top of Fedora 11 (for the first experiment) and KDE 4.6.5 on top of Gentoo (for the second experiment).