[geon]

> a pin, a password, a fingerprint, an identifying card or dongle

Those are all examples of authentication. Not at all the purpose of the slide-to-open.

The earlier dumb-phones used to have a key-lock functionality where you would have to press a certain combination of keys in quick succession. Or just open a physical lid.

[axman6]

My primary point still stands - the test isn't whether physical analogs exist, it is whether someone WOULD be lead to reach the same solution to the problem. I'm not sure I agree that someone, at the time, would have been lead to the same solution when the existing art revolved around physical mechanisms such as buttons and switches, and did not involve interaction with the screen which the mechanisms has previously been in place to prevent.