2.  An integrated circuit device transponder  Encased in a silicate glass  A.K.A RFID

3.  People have them implanted in their hands to switch on lights and open doors.  Even pets can use these for support.

4.  The microchip is similar to the microscope from the Scientific Revolution.  They both can look inside of things and identify information.  It can also determine what kinds of things you are ellergic to.

5. "Microchip Implant (human)." Wikipedia, the Free Encyclopedia. Web. 11 Apr. 2011. Heim, Kristi. "The Seattle Times: Local News: Man Grips Future with Microchip Implants in Hands." The Seattle Times | Seattle Times Newspaper. Web. 11 Apr. 2011.