Upgrading to Ubuntu 7.10 now, before the rush
To upgrade to Ubuntu 7.10 now, before the rush, by following these instructions:

1. Open a terminal window (Applications -> Accessories -> Terminal)
2. Run the following command:

update-manager -d (after Oct 18th, remove the -d option)

This will upgrade to the release candidate, which is considered complete and stable. On Oct 18th, apply the updates and you will be running 7.10 final release.

Note: This works only if you are running Ubuntu 7.04. If you are running an older version apply the upgrades in steps (for example, Ubuntu 6.10 -> Ubuntu 7.04 -> Ubuntu 7.10) using the update-manager. Otherwise you may break your Ubuntu installation.

Installing Ubuntu 7.10 Release Canidate
If you are not running Ubuntu download the release canidate ISO image and install it:
http://releases.ubuntu.com/7.10/ubuntu-7.10-rc-desktop-i386.iso
or http://releases.ubuntu.com/7.10/ubuntu-7.10-rc-desktop-amd64.iso

After installing Ubuntu using the release canidate ISO, apply updates on Oct 18th and you will be running 7.10 final release.

Downloading Ubuntu 7.10 Final Release
If you want to wait until the final release is available:
Try downloading from an Ubuntu mirror
Download the torrent, watch LinuxTracker.org