So I'm planning on making a To Do application this summer, but I'm having coders block on where to begin.

My motivation behind it is the fact I can't find a decent application to keep track of home work and other such things that works across all the OS's I use (Mac laptop, Gentoo Desktop, Windows at work).

I plan on using Python to code it and wxPython to create the interface. I've also thought about using Java or creating a Emacs plugin using Lisp. But Python has really started to grow on me.

What I need help with is coming up with a list of features and implementation ideas. I've been rummaging through the Gang of Four (Design Patterns) trying to get ideas of where to start, and how to go about it. But, I just can't come up with a good starting point and implementation strategy.

Any advice, ideas, etc. would be greatly appreciated. When I finish it I plan on releasing it as an open source project for anyone to contribute and use. Many tutorials and a development blog will probably come out of this.

Perhaps you should attack this from a different angle and create a list of what you hate about other applications used to manage work. Why can't you keep track of your work efficiently that you would need an app? What do you find yourself doing to keep up with a to do list?

Go to Google and type in the words "software to do list" and you will see a ton of results of software for managing work. Find the good ideas and flaws in them. Keep the good ideas and rework their flaws into other great features. Download one, try it out, find out what sucks about it (other than not being cross platform compatible). Is it too hard to add a task? Once added is it hard to manage? Can you add subtasks as part of one big task and make it a hierarchy? Can you setup goals and categorize tasks into various goals? Do they manage time lines to complete a task?

Once you start attacking other software and finding its weaknesses, these turn into ideas of how to make your software better and gives you ideas of features.

Always get a SOLID list of features before even touching code. Think of every possible scenario you can in which someone would want to use your software and then run through the steps of how you might solve that person's problem.

Then once you have a plan with a list of features, test case scenarios which have been worked out, then you can start work on construction.