On February 1, 2009, the Search and Rescue (SAR) satellite system will discontinue monitoring the frequencies broadcast by current TSO C91 and C91A ELTs (121.5 MHz and 243 MHz). The satellites will only receive the new 406 MHz signal after that date. However, the FAA is NOT planning at the present time to make any changes to FAR 91.207 (the regulation requiring ELTs in most airplanes). This means that your TSO C91 or C91A ELT will continue to meet the requirements of the FARs, even after February 1, 2009. However, these ELTs will not be monitored by the SAR satellite system, so they will be much less effective in alerting anyone should you have an accident. Note that Transport Canada will require 406 MHz ELTs at some point in the near future, so if your plans include flying to Canada you will need to upgrade the ELT in your aircraft regardless of what happens with FAR 91.207 in the U.S.