Which plugin: save posts to list

Could someone please recommend me a plugin:

I’d like to enable a visitor to my site to hit a ‘save’ or ‘remove’ button in a post, creating a personal list in the sidebar for all the posts he’d like to view after some further browsing on the site. Does such a plugin already exist? I saw this option on many listing websites and would really like it on my blog, but can’t find the plugin.