F1 visa to H1-b

I just completed my undergraduate degree and my F1 status does not expire till May 2010. My OPT application is in process and still pending with a requested start date of 10th February 2010. However, I have found an employer who is willing to sponsor my H1B visa. So here are my questions. i)Can my employer file for my H1B visa right now, even though I am interim OPT application process? ii) When can I start working and getting paid from my employer? Essentially, I want to start working and I am wondering what is the fastest way to do so.