Do you mean the Ubuntu Universe section? Ubuntu has a "universe" and "multiverse" in addition to the main one, whereas Debian has a "contrib" and "non-free" one.
You could use Ubuntu on Debian and vice versa, though there are some different naming conventions.
Both the Ubuntu and Debian ones are mirrored at OVH, found at "ftp://mir1.ovh.net/ubuntu" and "ftp://mir1.ovh.net/debian" respectively.
You can add these by manually editing the file "/etc/apt/sources.list" and appending them at the bottom with:
For example, for the Ubuntu Multiverse of Lucid (10.04 LTS), the URL would be "ftp://mir1.ovh.net/ubuntu", the distribution name would be "lucid" and the section name would be "multiverse":
Code:
deb ftp://mir1.ovh.net/ubuntu lucid multiverse
Similarly you can add these for Debian (ie, "lenny" and "non-free" if you would need Sun Java).
Once you have saved the file, you issue the command "apt-get update" so that it knows where to look for packages. If all went well, you should be able to use "apt-get install" or aptitude to install the package(s) you're looking for.