Directly, no. However, there is a way around this. You can create a redirect to your site. When you create a new Landing Page in ONTRAPORT, one of the options is Redirect. Creating one of these asks you for the domain of the page you want the Landing Page to redirect to. Use whatever domain you want (you can even use your own if it's nameservers are pointed to us) and then have it redirect to the page you want people to end up on. You can then create all the PURLs you want to the redirect page. You can even track who clicked the link!