TaskCard is a simple application that allows you to create to-do lists in the form of sticky notes, so you can have them all on your desktop. The cards you create can contain a name and a description, and you can customize their style, priority and status (delayed, in progress or canceled), assign a due date, and add reminders and repetitions. The cards can contain to-do lists or whatever comes to your mind, and you can even add pictures to them and customize the background color.
If you don't want to have lots of notes on your desktop, you can organize them in sheets (groups of cards) or nest them under only one card. A great thing is that the program allows you to sync your data with iCal and use Dropbox to sync multiple Mac computers. The trial version will only allow you to create three cards and it comes with a demo which shows you all the capabilities of the program in sticky notes.
Finally, if you want a nice and simple program to cease sticky notes with your to-do lists or important events, TaskCard can be done for you.