SpeedFreek, the pedal you refer to was the Aerolite. The titanium version is probably the lightest pedal ever produced, at 35g each. They were quite popular with the triathlon crowd. Personally, I found them more difficult to engage and disengage than other clipless designs. The engagement required a definite bounce with all your weight applied and there' was no aid to help position the cleat. The outward foot roll to disengage was not as natural as a foot twist. However, if you're a real weight-weenie, there is no substitute.

Edit: The Aerolite was a 1980s pedal system, not 1970s. I believe the inspiration occured in 1979 but the product did not come to market until the 1980s and was not popular until the late 1980s.