Methods and apparatus for delivering personalized (e.g., contextual) messages to a user that meets certain geographic, affiliation/metadata, timing, and/or or other criteria. These messages are geographically and logically persistent, and can be left by members of the user's social or “buddy” network,...http://www.google.com.hk/patents/US20080045236?utm_source=gb-gplus-share專利 US20080045236 - Methods and apparatus for gathering and delivering contextual messages in a mobile communication system
