Apt is the best friend for any deb dependend linux like debian , ubuntu etc.
You can speed up your apt by searching the nerestrepositery of apt (for your distro/linux)
I tested some tools to do this, APT-SPY shows the best performance
apt-spy is a program that tests a series of Debian archive mirrors for bandwith. It writes an /etc/apt/sources.list with the fastest server.
Run this command as su or root next thing will done by apt-spy, it will write a new /etc/apt/sources.list and the olde one will be backup with sources.list.bak
apt-spy -d unstable -n 5
here -d means which version
-n mean number of repositery will added source.list fine