Upgrading Ubuntu from 10.04 to 10.10 with a local mirror

I upgraded from Ubuntu 10.04 to Ubuntu 10.10 on my desktop today, using Update Manager. Since 10.04 is a Long Term Support release which features a long period of stability (bug fixes and security fixes only), 10.10 is not automatically offered. I had to hit the Settings button in Update Manager to bring up the Software Sources dialog, then the Updates tab and select "Normal releases" from the Show new distribution releases: drop-down menu in order to get the 10.10 upgrade to show up.