a few years ago i joined a post=card swap, for the year we all made postcards and actually mailed them to each other, i have a really cool 'scrap-book' filled with very creative quilted fabric postcards. they are fun to make, go right through the mail and are neat to save and show off.
i used 'timtex' interfacing, paper back fusable, lots of thread, muslin on the back (where you write) if sending through the mail you do need to be careful about embellishments, no buttons, beads that could come off.
they are way fun, so jump in and make a few...i will try later to take a few pics and put them on here :D