9. A system comprising: one or more computers; and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: identifying a user; receiving user input from the identified user through an interface associated with a web browser of a client device, the user input indicating a modification to a set of bookmarks for the identified user; in response to receiving the user input: modifying a set of bookmarks stored for the identified user in a client-side storage of the client device; and synchronizing the modified set of bookmarks with a server-side bookmark storage system configured to synchronize bookmarks for the identified user with one or more other client devices.
9. A system comprising: one or more computers; and one or more storage devices storing instructions that are operable, when executed by the one or more computers, to cause the one or more computers to perform operations comprising: identifying a user; receiving user input from the identified user through an interface associated with a web browser of a client device, the user input indicating a modification to a set of bookmarks for the identified user; in response to receiving the user input: modifying a set of bookmarks stored for the identified user in a client-side storage of the client device; and synchronizing the modified set of bookmarks with a server-side bookmark storage system configured to synchronize bookmarks for the identified user with one or more other client devices. 12. The system of claim 9 , wherein receiving the user input comprises receiving the user input through a user interface of provided by the web browser, a toolbar associated with the web browser, or a plug-in associated with the web browser.