@fabian: Yup. Just install Google toolbar, then access your printer's management interface through public IP, wait one or two days and they'll come.
Possibly work with other "toolbars" too.
This is the reason that I never install such "toolbars" on my machine at work. There was a catastrophic incident that a datacenter provide administration website for their customers but the website didn't bother to check access right on each page. Some user accessed it with browsers that has Google toolbar and got the site indexed (no robot.txt present). Anyone search for the datacenter company's name were free to purge the web space's content.