Slot machines and other devices are arranged to interact with the...http://www.google.ca/patents/US7878896?utm_source=gb-gplus-sharePatent US7878896 - Gaming token having a variable valueAdvanced Patent SearchPublication numberUS7878896 B2Publication typeGrantApplication numberUS 11/321,793Publication date1 Feb 2011Filing date29 Dec 2005Priority date10 May 2000Also published asUS7267614, US7549920