I'm rather endeared to the Bullova Accutron watch, which keeps time via a tuning fork mechanism (!) that drives the gear train. The watch also uses a one-transistor oscillator circuit, which qualifies it as the first 'electric watch'. As a special edition, Bullova released the 'SpaceView', with a clear face to see the mechanism. Incredibly lovely, don't you think?

The watch is far out of my price range (They go up on Ebay for $200-$300 in working order) and this is one time I'm questioning my instinctual response of 'too expensive? I'll just get a broken one and fix it!'.

(above image: Jeremiah O'Brien steam engine boiler detail by Nick Winterhalter)

Greasy machines bare all in camera close ups! Hot gear-on-gear action! ....Knobs!