Dead simple to-do's. Designed to stay out of your way, be easy to use, and look pretty.
I can't do any better than the above description from the developer's site, other than to add its free, and everyone who has seen it on my desktop immediately wants to know where they can get it.
Doomi is a super simple to do list manager.
Its great looking.
It needs Adobe Air (included with download) to run.
Its pretty. Its easy to use. Have a look.
Doomi requirements: Adobe Air