Drupal 7

For many bilingual websites, the standard Language Switcher block that comes with the locale module (shows both language links in one block)  will suffice.

A very useful module in D6 days called Admin Role. It attempts to convert the concept of the superuser (uid = 1) to a role; thereby allowing multiple users to be the superuser. Obviously a concept that should be in Drupal core.

Site development regularly extends beyond the launch of the site and beyond the point where the live site has real user accounts set up.