I came to US in August 2006 and I have been on F-1 visa since then. I started my OPT after July 2010 and working until now. I was wondering if I would be considered a resident for tax reasons or non-resident. In other words should I be filing 1040 or 1040 NR. Thanks for all your help.

For 2010 you will file nonresident tax return. Your U.S. Tax Return: U.S. Tax Filing Requirements for Non-Residents (http://taxipay.blogspot.com/2008/03/us-tax-filing-requirements-for-non.html)