It's not likely to work, but you've got nothing to lose, except possibly a case of carpal tunnel syndrome if you vote too many times. The E! Online website is offering a platform called SOS: Save One Show, where you can vote for the ratings-impair broadcast network series you'd most like to see back next fall. There are 17 different shows on the ballot, everything from Six Degrees to Supernatural, and E! Online columnist Kristin Veitch "will do her best to persuade network executives to pick up the highest voted show for another season."
I can assure you that Jeff Zucker and Les Moonves are about as likely to stand on their heads naked and eat a bug on Kristin Veitch's say-so as to keep a show they want to cancel. The networks don't care about what she or any other TV writer (including, astonishingly, me) thinks. For that matter, they don't care what you think either, only what you watch, and if the numbers aren't there, they aren't there.
The single possible exception to this ironclad rule might be The CW, where the audience is so infinitesimal that the mild publicity buzz generated by a commuted death sentence for a show on the ratings bubble like Veronica Mars or Gilmore Girls might add enough viewers to make it worthwhile for the network. Of the five shows Veitch claims to have saved with past campaigns, four -- One Tree Hill, Veronica Mars, Roswell and Angel -- were on UPN or The WB, the networkettes from which The CW was formed.
Some of the shows on Veitch's ballot are ringers (I don't think anybody believes that Scrubs is in serious danger of cancellation) and others are already dead meat. (Six Degrees and The Nine are not coming back to ABC next season unless you've got pictures of ABC programming boss Stephen McPherson cavorting naked with Donald Duck's underage nephews.) But a click or two for Supernatural or Veronica Mars couldn't hurt.