San Mateo, CA - http://epocrates.com working on an electronic health record system. If you have RoR && ( jQuery || moo || prototype.js || yui) skills, please email me. We use Shoulda, continuous integration (hudson), macbook pros with external monitors, &etc. This is a nice place to work with smart people -- we're working hard on the v1 of a new product, but have a midsize company's resources and maturity (benefits, experienced management, sane buy vs build mentality, &etc.)

It's also pretty cool to go into work each day and know that you are working towards saving lives and helping the medical industry.