Let's face it: you are an engaged, curious person, and you accumulate to-do list items like <your preferred simile here>: book and film recommendations, app and open source ideas, blog post ideas, restaurants and cafés to visit, things to see or do, online and off. These items are especially easy to accumulate if you use an app like TaskPaper, whose over-the-air sync enables universal capture of to-do items, whether at your Mac or while out and about on your iPhone.
Before long, you'll have more items on your list than you could conceivably do (even with all your ambition). These are great to keep around for reference or for that quiet weekend that needs filling, but in the end, they do little more than weigh you down and get in the way of the the important real-world things you need to do. Your to-do list shouldn't make you anxious.
Fortunately, TaskPaper offers another feature that will help you manage this problem: its simple single-file, plain-text data format. With TaskPaper, you can spread your to-do lists across multiple files, and have them open them concurrently. This is largely its reason for being, and what sets it apart from the heavier duty task management apps like OmniFocus. The benefit of this single text file is that you can easily move it and rename it, enabling you to shift everything aside and declare to-do list bankruptcy.
I've just done this myself, moving my
Things.taskpaper file to
Archive 2010.taskpaper. Bam: instant clean slate. Create a brand new
Things file in its place, copy across a select few important tasks, and you're ready to go. You can even keep your archived to-do lists in your synced SimpleText folder, so they remain accessible for reference on your iPhone as well as your Mac (There's nothing wrong with a security blanket if it doesn't get in the way).
There's much benefit to keeping your to-do list short. It helps you focus on the tasks that matter and actually achieve them. TaskPaper helps you balance these two by allowing you to contain and group your items by project and tags. Sometimes, though, it helps to have the less important stuff completely out of the way. Declaring to-do list bankruptcy is a simple, pain-free way to get started on this path. It's helping me to keep on top of the important things, and with publishing this post, I'll have one less item in the list. Now, onto the next thing!
 Another way would be to use a completely separate file for the "Someday" or "Maybe" tasks. A little more friction, but cleaner separation.