Wee Haggis,
Keep in mind the LUV vouchers which provide a 6 month extension to your TTF's are only valid for 6 months from the day you request the extension.
Example: My TTF's were expiring 4/20/06, I was not going to travel until the 25th of April. I requested the LUV vouchers on Nov. 16th and received them on Nov. 25th. They expire May 31,2006. That works for me, because our next trip is April 25th. But if I had wanted to use them for our Aug. trip I would have needed to wait until at least the end of Feb beginning of March.
So, my point is if you don't know when you will be traveling again, request as close to the current TTF expiration date as possible.
Also, these LUV vouchers can be used to purchase airfare online now, so we can take advantage of cheaper fares (dings etc.) This is a new system, unlike in the past when vouchers had to be used to purchase tickets at the airport.
Hope this helps.
Deb