You've got a great campaign running. Now you want to target the same users, but with some different ads at the same time. We make it easy to create new campaigns based on an existing campaign's settings.
To do this, click Manage-> Campaigns.
Click the checkbox next to the campaign you want to copy. Select Actions-> Create Similar Campaign.
You'll be taken to a campaign creation form with all of the settings in place from the campaign you selected. Feel free to make any tweaks to the settings, then launch the campaign as you normally would.