If you find that New Year's Resolutions aren't working for you, Day Zero is a website where you can undertake a more structured to-do list challenge, over a much longer time frame.
Describing itself as an internet meme, the 101 Things to do in 1,001 days project gets you to create a list of 101 things you want to achieve, with the criteria that:
"Tasks must be specific (ie. no ambiguity in the wording) with a result that is either measurable or clearly defined. Tasks must also be realistic and stretching (ie. represent some amount of work on your part)."
There's a degree of public accountability too - to sign up you'll need a website or blog, and your registration at Day Zero won't be accepted until your list appears on your website. Once it's up, you'll be able to add your list to the master list on Day Zero.
It's a nice idea to share everyone's lists publicly, particularly if you're searching for more interesting goals to add to your list than "clean out the garage".
Of course, if you don't really want to trumpet your goals to the world ("stop eating twinkies", "finally toilet train the cat" not really the image you want to project?) then this won't be the GTD project for you.
You can get some ideas and suggestions on how to get started here. And if you'd like to see how other people are travelling on their 1,001 day journey, you can check out the group blog here.