From the http://www.statesman.com/sports/content/sports/stories/other/09/5lance.html (site requires you to give some info)
"I'm thinking about it," Armstrong said. "I'm thinking it's the best way to piss (the French) off."
Armstrong said he has entertained the idea for only the past two weeks. He said he began thinking about it when a French newspaper reported Aug. 23 that he had tested positive six times for a banned blood booster as he was winning his first Tour in 1999.
When asked how serious he was about another Tour, Armstrong said, "I'm exercising every day."