@anidel
Actually in the iphone, you have "slide to answer" when the phone is locked (it shows a normal button only when you're using the device), even if the capacitive screen already prevents unwanted answering

I just ask about it because the "unwanted answering" was a really serious problem on HTC devices, and people at xda-developpers were trying several solutions to that:
- keep the screen locked when receiving a call (the screen is dimmed so you see who's calling, and you have to first unlock it, then press answer)
- slide to answer