A web site that helps doctors answer medical questions as they consult with patients. A maker of telephone handsets that tie together cellular and wide-area networks.  A social network on mobile phones that lets users rate each other. A site that gives parents access to a national sex offender database.

Those were some of the companies selected for the Red Herring 100 list of the best startups in North America for 2008. The winners were announced earlier this week at Red Herring annual North America 100 conference in San Jose, California.

Among the winners was San Mateo, California, startup Epocrates, whose site promises to add to the wisdom of medical doctors. Epocrates has signed up 500,000 health professionals to its suite of mobile- and web-based applications. Another was Mountain View, California, company Divitas Networks,  which sees a bright future in voice messaging over Wi-fi networks, helping companies cut their telecom bills.

Maybe only a bunch of savvy Australian entrepreneurs would have picked Funkysexycool as the name for their mobile social network, but after finding followers in Australia and Europe, the team relocated to New York City to spread their mobile rating system. And TrueScoop hopes to allay the fears that parents have of people who might prey on their children by giving them the ability to search their backgrounds.

A few, like Meebo–which unifies four instant-messaging systems via the web; and Brightcove, which manages online video–are already fairly well known. But many of the companies selected this year are still in their early stages.

The Red Herring 100 winners and another 100 finalists were chosen by the editors of Red Herring from more than 800 applications by companies based in the U.S. and Canada. They were selected on the basis of technology innovation, quality of management, breadth of partners and customers, and depth of financial backing.

The complete list follows: