You can use the Instant Ad feature to post your position to other job boards, such as Craigslist. You can also use it to copy the link to a specific posting.

To access the Instant Ad feature, navigate to the My Positions tab:
 

Then check the box next to the Position Title you wish to create the ad for, and select Take Action > Instant Ad from the top of the page.

This will bring up a lightbox, where you can copy the Instant Ad with a direct URL to your position.
 

Once the Instant Ad is copied, you can paste it into a job posting on additional job boards.