I have to admit that I don't use Apple's Dashboard widgets very often. Though I know there are several useful widgets available I think it might be that, in my business, I often search for a stand-alone solution to whatever the particular problem might be before thinking of Widgets. In other words, I think it's mostly just habit that I moved away from the Dashboard. But I came across an excellent free widget today that just might make me spend more time with widgets.
Organized, from iSlayer.com is a handy and elegant calendar widget which helps you keep your schedule organized. On the spare, but sleek tabbed interface you'll find handy world clocks for different time zones; Notes for reminders and thoughts; Events to give you a heads-up of the days appointments; and a ToDo tab for to-do lists. Each of the categories are very smartly done, with options like the ability to show due dates for your to-do lists, and the ability to create multiple calenders for separate tasks. What's more, it shares the same database as iCal and Mail, so whatever changes you make, you know you're always in sync.
Organized is a free Widget for Mac OS X 10.5, but in the interest of the continued development of cool programs, I should point out they politely request you consider a donation. I think once you see how easy it is to stay organized, and the way it works with iCal and Mail, you just might throw a few dollars their way.