I find adding a crank to anything quaint and hilarious. Even if just photoshoppedtm
A steam whistle that required a good crank and verifying subscrrription overrr dialup would end me
Edit: it must be a crank and it has to play the all around the blueberry bush progress song like the Sid’s handy jack in the box in Toy Story 1
Very, very rough numbers:
A recreational cyclist might average 150 Watts for 20-30 minutes.
A world tour pro cyclist would average 300-400 Watts over a few hours.
And then account for the inefficiency of the generator they are spinning.
Your average person could power a laptop, but not for very long. The battery in the laptop would help manage the inevitable spikes and dips in power output, since people are not consistent engines.