When we were having our DFTW our save the date was going to be that we were going to ship out rice crispy Mickey heads (We bought the cookie cutter so it was easy) and in icing (the kind you use on sugar cookies) write the date and attach a little card... We only had to send out like 7 though since our wedding was like 30 guests all families...
The other ideas that we had were:
luggage tags with the save the date inside of them
Mickey head magnets with the save the date on them
We had a few others when I remember I promise to post!
~Jenny