For riders, here's a Google form to submit your request: https://docs.google.com/forms/d/1r6LaI2snX-05mEIFSm8I9rurbOoXwpWrIoD919Cuklk/viewform

For drivers, here are responses from the form: https://docs.google.com/spreadsheet/ccc?key=0Ak3Y-RxtxPHjdGZITzFCNnN1Y0RVTUJpOWlKZmwteFE&usp=sharing

Drivers can contact riders through the rider's HN profile (please put email there if you want to be contacted) via https://news.ycombinator.com/user?id=<username>.