Can I change the list of available locales? Is it possible, by any method, to change the list of available locales? The current list includes some strange entries, e.g. East Germany, and we would like to update this to be more current for our client.
You can download the locales you want from https://github.com/yiisoft/yii/tree/master/framework/i18n/data and place in your craft/app/framework/i18n/data folder and they will show up as options.

Since Yii ships with so many locales, we initially stripped a lot of them out to keep the Craft download size to something reasonable.

If there are some locales we stripped that you think should be included in Craft, hit us up at support@buildwithcraft.com and we'll get them in.