Perhaps "what are you searching for?" Messages posted and available to read through that interface will be to and from your Google Contacts. (That's the people you Gmail with, basically.) Google is making a big push for people to take their Google Profiles more seriously and one consequence of that could be a well populated social graph for users.
Friends could help answer the questions you're asking of Google or they could let you know what they are doing, like a home town version of Google News.
M. Strohmaier, P. Prettenhofer, and M. Kroell. International Workshop on Agents and Data Mining Interaction ADMI ' 08, in conjunction with WI '08, (2008)
B. Krause, A. Hotho, and G. Stumme. Advances in Information Retrieval, 30th European Conference on IR Research, ECIR 2008, 4956, page 101-113. Springer, (2008)
Y. Yanbe, A. Jatowt, S. Nakamura, and K. Tanaka. JCDL '07: Proceedings of the 7th ACM/IEEE-CS joint conference on Digital libraries, page 107--116. New York, NY, USA, ACM, (2007)
J. Allan, and H. Raghavan. Proceedings of the 25th annual international ACM SIGIR Conference on Research and Development in Information Retrieval, page 307--314. ACM Press New York, NY, USA, (2002)