I've been keeping my selvages for the past decade or so because it used to really upset me to throw away fabric of any kind. I tend to cut the last inch or so of the fabric on the labeled side and much closer to the second side. I use the second side for tying things but the labeled side is pretty to me and perfect for some projects.
I keep the regular labeled ones sorted by color in a clear hanging shoe organizer and the special ones (30s all together, Modern designers Aneela Hoey & Heather Ross) sorted by color clear plastic bins.
So far, I've done mostly small projects like the pinkeeps/needle cases and pincushion below. I've made some selvage squares but have not made a whole top yet. I have friends who have made string quilts with them.
The old thread and tutorial can be found here:
Selvage Squares Tutorial
What do you use them for?