I've been using Uber in Chicago. Do they still not have it in St Louis? I feel like they've been talking about it, because I've seen spam e-mails from the company talking about St Louis.
They work with taxi's too. It use to be a pain for me to find a taxi at 4am , when, and if , I had to work that early. I can seriously call one with my phone, at 4am, and it'll arrive in front of my door, in under 5 minutes. They also have black SUV's and luxury cars, which I don't usually need, although I can see a situation where I may need one for work. If Im in a budget crunch, I can call for regular cars too.