Private browsing is awesome if you don't want somebody to see what you've been looking at, but if you do it (ahem) regularly, it can be annoying not having any bookmarks stored. Unbookmark is a service that lets you store bookmarks anonymously for use in private browsing sessions.
To create an Unbookmark account, you specify a passphrase to log in, and nothing else. The passphrase needs to include at least two spaces, two numbers and two capital letters. Once you've set it up, a letter within your sentence is changed at random. I understand why this is done — it reduces the odds of someone guessing a common sentence — but it does make the phrase a little harder to remember. There's no way of recovering your passphrase if you forget it; if that happens, you'll have to start again from scratch.
Once you've logged in, you can add whatever bookmarks you like. Any time you open a private browsing session, you can visit the page and log in using your passphrase. It's a bare-bones service, so there aren't any import options, but you can tag your bookmarks.
The service is still under development, and we experienced occasional glitches logging in, but it's an interesting idea.