Where's George? site says it "prohibits trading or exchanging bills with friends, family or anyone known to the bill distributor for the purpose of re-entry". This rule is to encourage natural circulation of the currency, and to prevent multiple fake hits from happening on any bill. As a result, all bill entry notes containing the word "geocache" or "cache" are tagged as a geocache bill. The site has also dropped a separate listing of "Top 10 Geocache bills" and is cautioning that, if geocache sites are used too often, "all Geocache bills will be removed from this site". George Score The "George Score" is a method of rating users based on how many bills they have entered, and by how many total hits they have had. The formula is as follows: This logarithmic formula means the more bills a user enters and the more hits the user receives, the less the user's score increases for each entered bill or new hit. Thus, a user's score does not increase as quickly when the user has entered many bills. User ranking can decrease based on inactivity (failure to refresh the "Your Bills" report). Wattsburg Gary, the user with the most bills entered (over 2 million entries per the Wheresgeorge database) has an official George Score of over 1,700 when refreshed, and often holds the #1 rank. While bulk entry is allowed, the site prohibits marking bills and depositing them into financial institutions. Community Where's George? includes a community of users who interact via forums. The forums divide into several categories, from regional to new-member-help threads. Some members of the site participate in "gatherings," held in cities around the United States. Several gatherings have become annual events, varying in scope and size. The 2006 documentary by Brian Galbreath, WheresGeorge.com, gives insight into the hobby, hobbyists, and their gatherings. The twenty-seven minute movie features interviews with site creator Hank Eskin, "Georgers" at a St. Louis, Missouri gathering, and narrated information and statistics about the site and culture. The film aired on PBS affiliates WTTW Chicago and WSIU-TV Carbondale, IL. Use in research Although Where's George? does not officially recognize the bills that travel the farthest or fastest, some have approached it as a semi-serious way to track patterns in the flow of American currency. Money flow displayed through Where's George was used in a 2006 research paper published by theoretical physicist Dirk Brockmann and