Do I need to extend my visa before applying for change of status to H1B?

Thanks for you inquiry. My recommendation to you is that you find a qualified attorney to review your case and advise you. The deal is that a "cap subject" H1-B will not be available with a start date any earlier than October 1, 2012. So if your B-1/B-2 status will expire prior to that time, I would very very cautious about filing a request to extend your tourist status and then change to an H-1B. USCIS has a number of "funny" interpretations about the meaning of maintains lawful non immigrant status following the expiration of one's Form I-94 and while an application for extension of status is pending. What the legal jumbo jumbo means is that you absolutely, positively need to make sure that you take the appropriate steps at the right time. Securing the "cap subject" H-1B is one issue. Making sure that you keep your status current or otherwise plan travel to use the H-1B correctly is something quite different. I cannot stress enough the importance of finding someone who can correctly advise you and make sure that you not only capture the visa, but are around to use it. This is one of those issues where a competent attorney is worth the price. Handle this incorrectly and you are looking at a world of trouble. Not trying to scare you, trying to send a little experience your way to make sure that you end up on the right side of things. Good luck.