This is the first of what I'm sure will be many questions before I leave for the US at the end of the year.

I'm going for my embassy interview for my J-1 exchange visa next Tuesday and I have a quick question about changing my status down the track.

I'm planning on arriving in the US to start my 12 months of work on the 2nd of December which means I have to finish working on the 2nd December, 2010. Now my closest friends live in the US and I hate the idea of leaving before Christmas; I'd like to spend one last Christmas/New Years with them. I already have a valid B1/B2 tourist visa which I'd like to use to stay until the beginning of January 2011.

What I'm wondering is a) if anyone has experience changing visa types while in the States and how hard it is and b) if this is something I should mention at my interview Tuesday or whether it's better left unsaid.

Thanks in advance.