I live in LA and found it (uber black sedan) to be 1.5 to 2x the normal city taxi rate. So I use the taxi magic app, and works great like uber. Although, most drivers prefer you pay cash unless it's a high fare.
This is making me glad I live in Bangkok. A 5 mile trip would cost less than $3 US, unless traffic is really heavy, and there's enough taxis everywhere that you almost never wait more than 5-10 minutes to hail one curbside. No fancy tech required.
