I'm not sure how long this has existed, but I only came across it recently. Abbey Road Studios, scene of so many classic Beatles (and other) recordings, has a webcam trained on the famous zebra crossing which featured on the cover of the 'Abbey Road' album.
Watch live (and with sound) as an endless procession of tourists annoy the hell out of drivers, as they have their picture taken aping the band's legendary pose.
Obviously better during UK daylight hours, to view the webcam click here.