Go Ape, the treetop adventure course with locations around the country, including Blue Jay Point County Park in Wake County, has a couple of deals on Sundays in November.
On the Treetop Adventure course, for ages 10 and up, two kids can swing from the trees for free with every full-paying adult.
On the Treetop Junior course, best for ages 3 and up, adults can go free with a full-paying child. I took my kids on the Treetop Junior course twice this summer (and we all loved it).
Go Ape's website has the details. It costs between about $28 and $58 to try out these courses (depending on the course you pick and your age). So this deal can add up to a pretty substantial savings.