Dalamser has introduced JAC [Just a Clock] 1.0 (http://www.dalamser.com/JAC/) for the Mac. It requires Mac OS X 10.6.6 or later, costs US$0.99 and is available at the Mac App Store in the Business category.
JAC provides one or more resizable traditional analog clocks showing the time in different locations around the world. The clock display is designed for those times when knowing the time and date is of primary importance. A number of JAC clocks can be arranged to echo the traditional “office wall” row of time zone clocks. These are all localized using the system language and calendar.
In addition to acting like normal application windows, clocks may be set tofloat above other applications. Clocks can also be brought forward using a Spaces/Mission Control aware hot corner.