Updated: Apr 3 1998 9:20AM

With the Paula Jones suit quashed and a majority of Americans calling for an end to presidential probes, now more than ever is the time for Ken Starr to prove the relevance of his Monica Lewinsky investigation. Which is why it's more than a littl e embarrassing that the independent counsel is going to spend Friday embroiled in a battle with a bookstore over a literary novel on the subject of phone sex.

Kramerbooks & Afterwords, a Washington bookstore, is going to court to fight a subpoena issued by Starr for records of books Lewinsky purchased there -- which, the Washington Post says, include Nicholson Baker's steamy classic, "Vox." Starr is well within his rights, but the first whiff of a First Amendment battle is likely to erode what little public support the prosecutor still has. "Ken Starr seems to give little heed to the basic right of all Americans to read what they want, free from government surv eillance," says Steven Shapiro, legal director of the ACLU. It's a powerful argument -- and with Barnes & Noble set to join the fight, it all makes for the kind of ding-dong courtroom diversion that Starr really doesn't need right now.

-- Chris Taylor