Posted: Wed Jun 11, 2008 3:22 pm-
You can only work for your current employer on your current O-1, but another employer can petition to get your another one. The same holds true for changing jobs.
"Change of employer . If an O-1 or O-2 alien in the United States seeks to change employers, the new employer must file a petition and a request to extend the alien's stay with the Service Center having jurisdiction over the new place of employment."
You would not be able to work outside your field unless that work also requires "extraordinary ability" and then the employer would still have to petition to bring you in on the O-1. This is all just about the O-1, but you could get another job if you can classify in a different category, like TN for example.