I am a bit late to the game here, but I wanted to say that Remember the Milk is a fantastic way to track your tasks. It’s a web based task management system and has a decent iPhone app. They do hook you with the app as it requires a Pro account to use after 15 days.
No more sticky notes, notepad and text docs spread across multiple computers (home, office, laptop), everything is right there. It is very easy to use and provides an API, which I will be taking advantage of for my Simple CRM. I highly recommend it. I do use BaseCamp for project management, and their ToDo lists are great, but I find using Remember the Milk to be easier, and faster. BaseCamp is good for the high level tasks and milestones, while Remember the Milk works very well for breaking out the high level tasks into smaller, more digestable chunks.
There are a few other options out there, depends on what you need. I recommend checking them each out!
