It is also possible to sync an entire wiki or to-do list using Dropbox. The most basic example of this, of course, is to simply throw a .txt file with your to-do list into the folder, but you can go much further than that. Your operating system does not consider your Dropbox folder to be any different from any other folder on your PC.
That means you can install a Wiki or To-Do program directly into the Dropbox folder and then use it as a fully synced entity.
Let's consider, for example, the Zim desktop wiki. This wiki installs on a computer and gives you a space that can be used to keep tabs on your life. You can add to-do lists, contact information, or use it to hold private journal entries and other thoughts. If you install Zim directly into your Dropbox folder your wiki will be automatically synced among all of your devices. This ensures that you always have your information at your fingertips no matter what device you're using. Zim, of course, is just an example - there are a lot of personal wiki options available and any of them should be usable alongside Dropbox.