Create your free wedding countdown clock, which you can embed in e-mail, use in your forum signature, or add to your wedding webiste.  Choose from a number of different designs, completely free from When Is My Wedding.  A sample countdown is below.

For a different style of countdowns, have a look at Daisy Path's free wedding announcements.  Instead of a countdown, these are more of a timeline to your wedding day.  You choose from several different timeline styles (such as the sunflower below), one of three markers (such as the doves below), then add some text and even a small image of your own.  These also can be used in e-mail, or forum sigs, etc.

Did we miss any?  Please let us know in the comments!