Clicking onto Apple's clock just to see the date can be quite annoying which led me to iclock ... what I found was SOOOO much more.
I still click up there now, but not when I need to see the date (that is now always visible :-), but when I want to plan my next weeks - saves me a trip into iCal so many times.
But that is just the beginning, whenever I need a 5 minute break I pick out one more feature of iClock to discover, getting another time saver every day ... for no extra charge :-D
quick access to system preferences, application switcher, menu customizer, timer, todo, ....

Once you gave it a try you will agree: amazing, amazing, amazing
Totally worth every cent!