I have the CX680i Sports earbuds from Sennheiser. These have a mic and an inline remote for controlling the phone. I haven't used such a setup prior to the 4S and Siri so I don't know how the voice activation stuff worked in older phones. But... I find that activating Siri via the earbud's inline remote (pressing and holding the play button) activates the screen on the phone. This seems counterintuitive because wouldn't it then be prone to accidental taps?