Mémoires is a modest piece of software with modest ambitions, but this simple journaling software brings off those aims with style and aplomb. It's basically a diary program with a calendar that helps you keep track of the entries. In many ways this approach is more or less the opposite of the excellent Journler, whose developer seems to take a kind of "kitchen sink" attitude toward features. Nonetheless, if all you want is a simple and stylish program to keep a journal this might be just what you need.
Mémoires is in beta and available for download from Coding Robots.