albion, As you failed to answer my question about 650 v's 700c wheels I'm assuming you don't know how to reference the gearing to a different wheel size. This is actually becoming more important with the slow decline of the 650c standard with competition bikes moving to 700c & other factors pushing towards narrow 26" rims moving across wheel sizes has become more important.
Gear inches are used almost universally for gearing notation of a bike because it gives an absolute figure on the gear. In mathematical terms you're simply multiplying your beloved gear ratio by the wheel diameter. Hardly complicated of difficult to comprehend, in fact it's easier for the human brain to comprehend a dimensioned number rather than a dimensionless one as it brings in a physical reference.
FYI If the pedal spindle is moving at 1.5m/s there is nothing that the depth of the sole can do which means your foot moves faster or slower than 1.5m/s, it just moves its centre relative to the BB centre line.
screenman, it effect how much power you can put into the pedals at a given rpm. You see power actually references foot speed not cadence. On any given day regardless of what length I'm using I will always produce the same amount of power for the same muscular effort level at a given pedal speed be it 98rpm on 175mm cranks or 107.5rpm on 160mm cranks. If I keep the gearing inches the same this means the road speed at which that power is produced changes.
As an example say we have a petrol engined & a diesel engined car & both produce 200bhp at 100mph in top gear & both red line at 150mph. The petrol engine revs to 7500 & the diesel revs to 5000rpm. If we swapped the gear boxes over the petrol car would be producing 200bhp at 150mph & red line at 225mph the diesel would be producing 200bhp at 67mph & red lining at 100mph.
