What needs to be done
In the short-term:
Get the university statisticians on the case to explain if the irregularities in Florida, Ohio, and elsewhere are plausible, not just possible.
Get some research assistants and graduate students on the case to examine precinct by precinct if any vote totals exceed voter totals, or if any numbers seem to keep popping up, betraying a naughty algorithm. (See Atrios' experience in Ohio.)
Compare and contrast the 2000 results with the 2004 results county by county to demonstrate if Bush's 2004 success in heavily Democratic registered counties in Florida is an anomaly or not.
If enough irregularities emerge, push for a paper ballot recount in Ohio, where, unlike in Florida, there is, so I hear, a mechanism in place for recounts to occur.
Continue to encourage other Democratic congressmen to join with Conyers, Nadler, Wexler, et al, and hopefully draw out Senators to support an examination and investigation -- more than likely, Democratic Senators with incredibly safe seats, such as Pat Leahy (VT), Jack Reed (RI), Chris Dodd (CT), and Ted Kennedy (MA).
Remind John Kerry that concession speeches are not binding or legal, and that Richard Nixon was contesting Hawaii through December of 1960.
Get more members of the mass media to cover the story. Remember the Trent Lott story and the CBS-Rather story. Things start in the blogs and then break out. This is already starting to break, with Olbermann taking the lead. This needs more print exploration. The debunking that has happened so far has been far from enough.