Hush is a great add-on for Firefox that allows you to create and access secure bookmarks while private browsing. These bookmarks will be ones that you and you alone can access. So if privacy is important to you, you need to give this add-on a shot.
Here is a little more about Hush from the developers:
Hush is an extension we’ve created to solve this problem. It runs only during private browsing and so doesn’t disrupt everyday work, but when you really need to bookmark your surprise party plans, et cetera, you can do so easily from the address bar. The next time you’re private browsing, it’s really easy to bring up pages you’ve bookmarked in the past. You can also easily make multiple sets of bookmarks by choosing a different password for each set.
Want to learn more? You can pick up Hush at the Firefox Add-ons website.