These are taken from our County Fair Youth Exhibit categories, so take them FWIW:
Leaf Collection
Nature craft (pinecone crafts, items from driftwood, etc.)
Craft from recycled materials
Squirrel feeder
Squirrel or duck box (or other wildlife, such as bats)
Fishing lures
Bookends
Key holder or keyring
Mosaic
Collage (my ds8 made a “pizza” using cardboard for the crust, red paper for the sauce, and paper and felt for the toppings. He got a blue ribbon for it, too.)
Model airplane, rocket, car
Arrowhead, Sports card, coin, rock, shell, stamp collections
Seasonal and holiday crafts (for fall, there are all sorts of pinecone crafts, apple prints, potato printing, leaf crafts)
Bookmarks (would make good gifts)–boys might like to make them from paper or fun foam
Homemade soap
Leather crafts
Metal crafts
Rock or seed art (find interesting rocks and paint them; use seeds to create a picture)
Sand art
Stepping stone
Make a terrarium
If he would rather glue than use nails (or if it would make you feel better), I saw these kits at Wal-Mart:
http://www.walmart.com/ip/Value-Craft-Paint-Your-Own-Wood-Airplane/20934834
There are other similar kits, too.
HTH,
Karen