9. The computer-readable medium of claim 8 , wherein the method further comprises notifying the first user when at least one friend has annotated an electronic document.
9. The computer-readable medium of claim 8 , wherein the method further comprises notifying the first user when at least one friend has annotated an electronic document. 10. The computer-readable medium of claim 9 , wherein notifying the first user comprises performing at least one of the following operations: sending an email; sending a text message; posting a notice on the first user's Really Simple Syndication (RSS) reader; and posting a notice on the first user's login page.