You can use them to decorate the front of a chipboard album or journal.
This sample uses mostly smaller fragments because it was a 5x7 chipboard album.
I also have seen people alter wooden photo frames with them.
In addition to backing a fragment with paper, you can add a rub-on. For example you can spell out a person's name with rub-on letters and then use them to decorate a frame, journal, etc.
If you buy the round/oval ones that have the pre-driled holes, you can make jewelry with them (earrings, pendants).