http://distrowatch.com/table.php?distribution=ubuntuDownload linksOr order for free. Only for Ubuntu or Kubuntu (Ubuntu using KDE desktop)
https://shipit.ubuntu.com/login --> For Ubuntu
https://shipit.kubuntu.org/login --> For Kubuntu
You need to sign up first before you can order for free. Takes up to 6 weeks for delivery.
The other distros that are based on Ubuntu are released as well:
http://www.kubuntu.com/ --> Kubuntu
http://cdimage.ubuntu.com/xubuntu/releases/gutsy/rc/ --> Xubuntu
http://www.edubuntu.org/ --> Education version of Ubuntu
http://www.mythbuntu.org/ --> Mythbuntu
http://cdimage.ubuntu.com/gobuntu/daily/current/ --> Gobuntu, everything open-sourced
http://www.ubuntume.com/installation --> Muslim Edition of Ubuntu, not quite updated yet
Edit: Updated links
You can order a maximum of 2 CDs, either 32-bit or 64-bit.
PPC not supported.
For other amounts of CDs, or a mixture of both 32 and 64 bit CDs, use the Special Requests link.
