I'm A IMG on J-1: 2 year requirement

[Morpheussion]

I have a question, I currently have a J-1 visa and I'm planning to go back to my country and do the 2 year requirement, I'll do a fellowship in 2007 and I'd like to know how difficult is to get the HIB visa before i start me fellwoship in 2007. At what time can I apply for a H1B visa before I start my fellwoship?

Thanks.