Hi Archer,
I'm currently working in the US under a J1 visa. It's my understanding that to change your visa status you need to have a sponsor (i.e. an employer) that supports your application. So first you get yourself a job and then your new employer asks the INS to change your visa status. And they have to show that you are the best qualified person for the job and you are not taking a job away from an American citizen. I've been told that this process doesn't take too long and is a LOT shorter than applying for your first visa. Hope this helps in some way...
tess.