From a technical point of view the tickers can come in several varieties. The most common are Server side, Flash and html with server side being the most compatible. The server generated tickers are just a link to an image file that you can put anywhere. The one concern is that the image file cannot be being stored by a another server along the way or your ticker will not update.
Flash and html tickers are also very popular and can produce great results. However, they may not work with as many sites so you need to check that they will work where you want them.
Counters and Sliders are the two basic designs for tickers. Counters have a numerical countdown on the image and it changes to reflect how much time is left to go. The sliders have a small icon that moves along a path to represent how much time is left to go.
Alway be aware that when you use tickers you are putting a piece of person information out on the web for the whole world to see. But you are putting a limited amount of information and nothing that is that secure. But you always need to be careful. Remember, once you put a ticker out you have made your due date public to the whole world.
