Windows only: Free application TimeLeft is a Swiss Army knife of time-related utilities, including reminders, countdowns, timers, stopwatches, auction watches, and more. If you want to keep track of something timely, TimeLeft can help.
Need to set a quick reminder? Fire up TimeLeft and add a new one. Want a countdown to lunch? Set one up with TimeLeft. When you create one of the many clocks or reminders, TimeLeft displays small, widget-like floating windows to keep you abreast of the situation. You've got options to customise the timers however you'd like, including transparency tweaks and always-on-top toggling. It's an app you have to spend a little time unpacking, but for the right kind of work, it could be very useful.
TimeLeft is a free download, Windows only.