That would be an great app. The user could globally set their fake name and email address -- for example I'd use my old Yahoo mail that I keep for spam storage

That would be an great app. The user could globally set their fake name and email address -- for example I'd use my old Yahoo mail that I keep for spam storage... in the cloud(tm)!!! The app could query and update a central store of signup sequences for known sites (the names & order of the fields to supply, or even a sequence of fake keystrokes to send when the time comes, kind of like KeePass's auto-type feature).