In a case more interesting for its facts than the law, the US District Court for the Middle District of Alabama recently considered whether the attorney-client privilege extended to an independent contractor of the client. Hope for Families v. Warren, 2009 US Dist. LEXIS 46009 (April 21, 2009). It's a good refresher and relies particularly on an Eight Circuit case for its ruling. In re Bieter Co., 16 F.3d 929 (8th Cir. 1994). The general answer is yes it can.
Now for the facts. The independent contractor was a former state senator and lieutenant governor hired by a bingo parlor to (1) secure a document signed by the county sheriff authorizing Lukcy Palace to operate a bingo parlor (2) find an opponent to run against the sheriff and (3) run the campaign. Apparently the lawsuit involved claims that the sheriff was conspiring with others to create a bingo monopoly in the county. Think big Macon. Sheriff Warren was re-elected.