Wunderlist is a web and mobile app that allows you to create multiple to do lists. You can organize them by priority, deadline, or alphabetically. For me, it's the best because I can combine my home, financial, shopping, school, and volunteer to-dos in one place!
You can set Wunderlist to remind you about the task, or you can choose to check in on your own.
I'm totally hooked on Wunderlist... check it out!