Put Word of Mouth on your Web site as a chat room: Anonymity is the accepted norm in that medium. Folks who don't have access to the Internet at home could call the WOM number and your Web staff could put their comments there for them. They can go to the library to see their comments online.
Take the topics that show up in it regularly and assign a reporter to do stories on them, properly researched and documented, that you print in the paper. You can thank your anonymous sources for the tips.
Given the latest little flurry of comment, maybe a retrospective of the role of anonymous journalism would be interesting and enlightening. Think Watergate, think Monica. A timely discussion in the New York Times this morning: http://www.nytimes.com/2001/02/07/politics/07MET-GORE.html, and here's a great discussion with Bob Woodward on that topic: http://www.pbs.org/newshour/bb/media/july-dec98/sources_9-30.html. Do anonymous sources represent a "conspiracy on the part of the press and source in restraint of public truth?" Maybe we would all learn something.
As it is, unfortunately WOM seems to set the tone for the entire paper, detracting from the real and fine work or journalism that several of your reporters do regularly. Your editorial decision to print it has got to be demoralizing, denigrating as it does the entire reason for careful journalistic work.