wissel.net

Unless you are hiding under a rock, you develop mobile XPages applications. Since emulators only get you so far (the iOS emulator only runs on Mac where you don't have a Domino Designer), you want to test the app on the real devices (after you convinced your boss to buy all them). For "always on" developers with access to a development server that isn't an issue. When you are "on the run" and all you have is Domino Designer, it just doesn't work. When you try to connect to your Domino Designer "Preview in Web Browser" from anything else than localhost (127.0.0.1 or ::1) you will get an Error 500 Access violation.
With a little creative configuration you can get around it! Review this post and you (almost) know what to do. Instead of "proxy mode" you use "listener" mode, let's say port 88. Configure the target address to 127.0.0.1 Port 80. Once set you can connect to your HTTP preview from "outside" on port 88. This can be the iPhone emulator on your OS/X host talking to the Domino Designer Web in your Windows VM or any mobile phone talking to your local real or virtual machine. A little step for a developer... Of course: local preview doesn't magically support authentication (I tried really hard hacking the local names.nsf), so you need a real server to test that one.
As usual YMMV