Taxihack allows users to post live comments on NYC taxis and their drivers via email (alert@taxihack.com) or Twitter (@taxihack). Users send messages to the system, including either the medallion number (like 1A23) or the driver's number (located on the driver's id visible in the backseat). The site then posts the comment on the appropriate pages for public viewing, and sends a message back with the URL.

The site also exposes a information about the taxi industry that has previously been opaque. For instance:

• Taxi company information (example): We show all the medallions owned by a company. Also, we scrape the NYS corporation search results for more info, including the address.
• Possible drivers for a cab (example) & possible cabs for a driver (example): This comes from a PDF located on the nyc.gov TLC site.

As the user comments on taxis, we save each one that could serve as a record of the cab rides they've taken. If the user comments via Twitter, the profile page uses info from their Twitter profile (example). If they contribute via email, we take a more low-key approach, just identifying them by an anonymous ID (example).