Are you the list-making type? Grab this application for the iPhone, which helps you manage your tasks and to-do lists. You can also use it with the Mac OS X client, so you can sync tasks from your Mac to your iPhone. You'll need to register to get started.
iPhone Link: http://www.easytaskmanager.net/iphone/index.html
Web site link: http://www.easytaskmanager.net