Here's a link with ideas for fence boards:
Fence pieces make a great base for painted signs, and could also be used as a back on a bench or chair. The pieces could also be used as an outdoor table top... I hope this helps!
You could make a shiplap wall somewhere in your house. Or you could make shelves with your fence boards.
You could make a bird feeder. I'm getting some ceder fence boards from my daughter next week. She wants me to make beer sampler holders like you see at craft beer pubs. Each holder will hold a few glasses so they can put in beer and cider samples.