DisplayTimer adds a clock displaying UTC time to the bottom toolbar. This is helpful in figuring out how long ago comments were posted on talk pages and forums since the user's signature shows the time in UTC when it was posted.
Bonus features: Clicking the clock will purge the current page, and holding 'Shift' key while clicking the clock will null edit the current page (like NullEditButton).
This script has no customisation options and is a simpler alternative to the UTCClock script. It is also compatible with vanilla MediaWiki wikis (like Wikipedia), where the time will be added to the personal portlet at the top of the page.