I first mentioned Shuan Sullivan’s free iPhone emulator in the,”Top Ten Email Preview Tools” post. He recently updated iBBDemo, to include iPad and PC/Mac/Linux support.
New functionality includes the ability to view in portrait or landscape mode, as well as keyboard shortcuts (Ctrl 1 & 2) to toggle between each device.
While not as accurate as DeviceAnywhere – which I use in tandem – its a handy free tool. I use it to preview emails in my Gmail account and check out mobile websites from my PC.