ZocDoc is a free service that allows patients to book Doctor appointments online in New York City. It started in September 2007 as a service to help people find and make dentist appointments in NYC, and has now includes other specialties too (like primary care, dermatologist, ENT, ortho, OB/GYN, allergist, podiatrist, etc.)
Patients get to use the site for free- looking up physicians that accept their insurance and setting up appointments with them. Apparently, physicians need to pay to join ZocDoc and their enter availability info. Given their recent start, focus on one metropolitan area, the monthly unique visitor count is significant (20K+ according to dataopedia).
Interesting idea overall, kind of OpenTable.com for clinical care. The fact that you can set up a guaranteed appointment with a care provider today is a great feature (hard to execute in all cases though). What blows me away is the backing they have- Khosla, Bezos and Benihoff! That has got to be the most incredible investment partner team I’ve seen so far in any small healthcare IT startup.
September 2010 Update: ZocDoc is now in San Francisco, Chicago and Washington D.C. too.
September 2011 Update: ZocDoc raised another $75M in Series C, bringing their total to a unbelievable $95M. It now officially the Healthcare IT startup with most adrenaline.
October 2013 Update: Whoa! Zeel now only shows massage therapy scheduling. I guess the previous focus was too broad (or the mass market really cares about getting massages coordinated.. ahem.. privately)