I got my H1b in OCT 2007. I went to my home country last year and got H1B visa stamping for Dec 31,2011. Can I work till Dec 31,2011?

Thank you for your question.  You can continue to live and work in the U.S. as long as your I-94 form is valid.  The I-94 form is the square document that is usually stapled into your passport when you arrive in the U.S.    Your visa in your passport may expire on a different date than your I-94 form, but the I-94 form controls your status within the U.S.  You can apply to extend your status up to 6 months before your I-94 form expires, but I suggest that you file at least 3 months in advance.  Good luck! Mark J. Curley www.curleylawoffice.com