We booked relatively 'late' for a Disney vacation as it was semi-last minute for us. I am the obsessive Disney planner! So, as soon as SW opens up the dates, book the flight and sign up for DING now. You will start to receive the dings and you can familiarize yourself with how it works. I can explain how to cancel and re-book later if you like. Someone else on the DIS had written up a very simple way to do this. Don't worry, I was scared the first time I did it, but now it's sooooo easy. When the DING comes up, hit the botton just to see how it shows up (you aren't committing to anything!). It just shows up as an extra button/tab to hit to purchase. Very cool! You will have to cancel the booked flight and it automatically goes into the 'credit bank'. You also get a cancelation #. KEEP that # handy. Then you apply the cancelation # to the new rebook and it transfers over the $$$ from the bank to the new booking. Then you get another screen that will tell you how much you have for a credit with SW. I forgot one of my dings and forgot that I had 2 separate banked amounts because I got two DINGS and therefore two credits. It isn't all kept in one bank and that's the only confusing part. So, just print each time you do a DING to keep track of your banked $$. So, no money gets credited to your credit card account and therefore no charges by SW to change flights, etc.! Sorry it's so long, but I am very excited about this for me and anyone else who wnats to save alot of $$.