When reading news in Google Reader, I have the habit of quickly skimming through the posts and sending the more interesting ones to background tabs for future reading. However, there is no keyboard shortcut to do that. Hence, I made my own little Safari Extension to do so:
Download it here. Once installed, hitting the ‘b’ key when using Google Reader will send the current story into a background tab. Let me know how it works for you in the comments below.