[necubi]

Lyft penalizes you $5 for cancelled rides after some amount of time, at least in SF. Also when the app makes a request on its own and you're not there.

[fragmede]

As does Uber - they'll charge $10 if you cancel after 5 minutes after the driver is assigned.

http://blog.uber.com/2012/05/01/updated-cancellation-policy/

[georgeott]

Uber charges the same $5 after 5 mins, if cancelled.