I just bought a Tracfone to use for emergencies. I noticed that existing users can refer new users and each party gets 100 free minutes (~$30.00). I haven't activated mine yet, so if anyone wants to refer me, send an instant message with your email address and I'll email you with mine. Details of their offer:
http://www.tracfone.com/safc.jsp?task=promo&bid=60
http://www.tracfone.com/safc.jsp?task=promo&bid=60