10. The method of claim 9 , wherein the criterion includes a keyword.
9. A method comprising: receiving, at a server device, annotations from a plurality of client devices; identifying tags associated with at least a portion of the annotations; forming a group associated with a plurality of members, each of the plurality of members being associated with a client device of the plurality of client devices; receiving a request from a respective client device of a member of the group to obtain tags utilized by an additional member of the group and matching a criterion specified by the request; identifying a tag that is utilized by the additional member of the group and that matches the criterion of the request; and sending the tag to the respective client device.